[2025] SASC 80

Prosecution: THE KING Counsel: MS J LITSTER - Solicitor: DIRECTOR OF PUBLIC PROSECUTIONS (SA) Accused: CYNTHIA ELLEN RIGNEY Counsel: MR S MILLSTEED KC - Solicitor: ABORIGINAL LEGAL RIGHTS MOVEMENT Hearing Date/s: 08/09/2022, 12/09/2022 to 13/09/2022, 20/09/2022, 23/09/2022, 31/10/2022, 30/01/2023 to 31/01/2023, 16/02/2023, 06/07/2023, 08/08/2023 File No/s: SCCRM-19-323 B SUPREME COURT OF SOUTH AUSTRALIA (Criminal) DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment. The onus remains on any person using material in the judgment to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court in which it was generated. R v RIGNEY Criminal Trial by Judge Alone [2025] SASC 80 Reasons for Decision of the Honourable Justice Bampton 30 May 2025 CRIMINAL LAW - GENERAL MATTERS - CRIMINAL LIABILITY AND CAPACITY - DEFENCE MATTERS - INSANITY AND MENTAL IMPAIRMENT CRIMINAL LAW - PARTICULAR OFFENCES - OFFENCES AGAINST THE PERSON - HOMICIDE Accused charged with murder – accused pleaded not guilty by reason of mental incompetence – investigation under Part 8A of the Criminal Law Consolidation Act 1935 (SA) – Court determined to proceed first with trial of the objective elements – finding recorded that objective elements established beyond reasonable doubt – whether accused mentally incompetent to commit the offence. Held: Presumption of mental competence not displaced. Criminal Law Consolidation Act 1935 (SA) Part 8A, ss 269A, 269C, 269D, 269G; Mental Health Act 2009 (SA) s 56, referred to. R v Bonython (1984) 38 SASR 45; Christie v The Queen [2005] WASCA 55; Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705; HG v The Queen (1999) 197 CLR 41; Ramsay v Watson (1961) 108 CLR 642, considered. -- 1 of 114 -- -- 2 of 114 -- R v RIGNEY [2025] SASC 80 Criminal: Trial by Judge Alone The residents of Goodman Avenue, Kilburn .................................................... 3 Ms Rigney’s movements on 7 December 2018 .................................................. 4 Ms Rigney’s attendances at Cash Converters and Service SA .................................................. 4 Ms Rigney’s attendances at the Luis premises .......................................................................... 4 The attempts to raise Maria Luis and Chico Luis’ return ......................................................... 6 Ms Rigney stabbed Maria Luis .......................................................................... 6 The arrest of Ms Rigney ...................................................................................... 6 Ms Rigney’s police interviews on 7 and 8 December 2018 ....................................................... 7 DNA analysis.............................................................................................................................. 8 Ms Rigney’s personal circumstances and mental health history .................... 8 Ms Rigney’s admissions for mental health issues prior to 7 December 2018 ........................... 9 Ms Rigney’s mental health history following her arrest .......................................................... 14 Fitness to plead and mental competence ......................................................... 16 “A tiger by the tail” ................................................................................................................. 16 The trial pursuant to s 269G of the CLCA ...................................................... 18 The test for mental competence................................................................................................ 19 Intoxication excluded ........................................................................................................... 20 Ms Rigney’s mental impairment .............................................................................................. 22 Dr Nambiar .............................................................................................................................. 23 Dr Nambiar’s report dated 26 March 2020 .......................................................................... 23 Dr Nambiar’s report dated 20 July 2020.............................................................................. 24 Dr Nambiar’s report dated 8 February 2021 ........................................................................ 25 Dr Nambiar’s report dated 28 April 2021 ............................................................................ 26 Dr Nambiar’s report dated 26 July 2021.............................................................................. 27 Dr Nambiar’s evidence ........................................................................................................ 27 Cross-examination of Dr Nambiar ....................................................................................... 30 Dr Ferris .................................................................................................................................. 36 Dr Ferris’ reports dated 21 August and 20 September 2020 ............................................... 36 Dr Ferris’ report dated 23 March 2021 ................................................................................ 37 Dr Ferris’ report dated 30 April 2021 .................................................................................. 39 Dr Ferris’ report dated 26 July 2021 .................................................................................... 39 Dr Ferris’ evidence .............................................................................................................. 40 Cross-examination of Dr Ferris ........................................................................................... 45 Dr Furst.................................................................................................................................... 50 Dr Furst’s report dated 2 May 2022 ..................................................................................... 50 Dr Furst’s evidence .............................................................................................................. 52 Cross-examination of Dr Furst............................................................................................. 54 Prof Coyle ................................................................................................................................ 59 Prof Coyle’s report 28 July 2022 ......................................................................................... 59 Prof Coyle’s consideration of Dr Nambiar’s reports ........................................................... 62 -- 3 of 114 -- [2025] SASC 80 Bampton J 2 Prof Coyle’s consideration of Dr Ferris’ reports ................................................................. 63 Prof Coyle’s consideration of Dr Furst’s report .................................................................. 63 Dr Nambiar’s report dated 10 August 2022 responding to Prof Coyle’s report .................. 64 Dr Ferris’ report dated 15 August 2022 responding to Prof Coyle’s report ........................ 65 Dr Furst’s report dated 22 August 2022 responding to Prof Coyle’s report ........................ 65 Prof Coyle’s evidence .......................................................................................................... 67 Cross-examination of Prof Coyle......................................................................................... 71 Re-examination of Prof Coyle ............................................................................................. 76 Prof Morris .............................................................................................................................. 76 Prof Morris’ reports dated 22 August 2022 and 28 August 2022 ........................................ 76 Dr Ferris’ report dated 29 August 2022 responding to Prof Morris’ report ........................ 78 Prof Morris’ evidence .......................................................................................................... 78 Cross-examination of Prof Morris ....................................................................................... 82 Re-examination of Prof Morris ............................................................................................ 85 Defence submissions .......................................................................................... 85 Diagnosis of mental impairment .............................................................................................. 86 Purposeful conduct .................................................................................................................. 86 Motivation for the stabbing ...................................................................................................... 87 Ms Rigney’s lack of memory of the stabbing ........................................................................... 88 Absence of self-report from Ms Rigney regarding symptoms during the stabbing .................. 88 Expertise and experience of Prof Coyle and Prof Morris ....................................................... 89 Dr Nambiar’s change of position............................................................................................. 89 Ms Rigney’s false account of the stabbing ............................................................................... 90 Dr Ferris’ change of position .................................................................................................. 91 Admissibility of Dr Ferris’ evidence regarding memory ......................................................... 92 Prosecution submissions .................................................................................... 94 Collateral evidence supporting mental competence ................................................................ 95 Criticisms of Prof Coyle and Prof Morris ............................................................................... 95 The psychiatrists called by the prosecution ............................................................................. 97 Discussion ........................................................................................................... 98 Conclusion ........................................................................................................ 111 -- 4 of 114 -- [2025] SASC 80 Bampton J 3 1 BAMPTON J: Maria Luis and her husband, Francisco (“Chico”) Luis, were known by their neighbours as the local cannabis dealers. For many years, they lived together in a semi-detached house on Goodman Avenue, Kilburn, out of which they transacted business between 9:00 am and 9:00 pm. Chico Luis told South Australia Police (“police”) his wife took care of the cannabis sales, which involved selling bags to people she knew and trusted. He also reported Maria Luis having told him she did not sell cannabis to Aboriginal or young people. 2 Maria Luis was killed near the front door of her home on 7 December 2018 following the infliction of 34 stab injuries by Cynthia Rigney (“the stabbing”), who has been charged with her murder. Ms Rigney, who also lived on Goodman Avenue, has treatment-resistant schizophrenia. She says she has no memory of the stabbing, and that she was mentally incompetent as defined by s 269C of the Criminal Law Consolidation Act 1935 (SA) (“the CLCA”) at the time of the stabbing. The residents of Goodman Avenue, Kilburn 3 Noel Uhe was another Goodman Avenue resident. He reported that he was aware Maria and Chico Luis sold cannabis from their home, having himself purchased small plastic seal bags of cannabis for $50 each from them. He recounted attending at the Luis front door and being served by either Maria or Chico Luis, on their front porch. Noel Uhe said Ms Rigney had asked him to get her some cannabis from Maria and Chico Luis but denied ever doing so. Another neighbour reported being asked by Ms Rigney in early November 2018 to buy cannabis from Maria Luis for her. The neighbour told Ms Rigney she did not know Maria Luis and did not accede to the request. 4 On about 2 or 3 December 2018, Kirsty Francis, a neighbour of Maria and Chico Luis told police she saw Ms Rigney screaming and approaching the Luis front porch. Ms Francis said she confronted Ms Rigney and the following exchange took place: Ms Francis “snap out of it, that is [someone’s] mother, have some respect” Ms Rigney “are you starting on me” Ms Francis “whatever you want to call it, stay the fuck away from her house” Ms Rigney “well can you get me a bag then” Ms Francis “no” Ms Francis inferred Ms Rigney was referring to a bag of cannabis, as she was aware Maria Luis sold cannabis but never to young people. -- 5 of 114 -- [2025] SASC 80 Bampton J 4 5 Several of Ms Rigney’s neighbours, as well as visitors to the area, have provided accounts of Ms Rigney’s erratic and aggressive interactions with them during the time she lived on Goodman Avenue prior to 7 December 2018. Ms Rigney’s movements on 7 December 2018 Ms Rigney’s attendances at Cash Converters and Service SA 6 On 7 December 2018, Ms Rigney attended Cash Converters, Prospect to obtain a cash advance loan. She was informed she would require 100 points of identification to apply for the loan. By reference to the statement of Blake Horder sworn on 4 March 2019, Ms Rigney received a MyGov security code by text message on 7 December 2018 at 12:02 pm and a text message from Centrelink at 12:31 pm confirming she had registered for “Centrelink self service”. Ms Rigney then made her way to Service SA, Prospect to obtain further documents to satisfy the 100-point identification requirement. 7 At 12:51 pm, Ms Rigney was captured on CCTV at Service SA, Prospect wearing a green “Stussy” T-shirt, light and ripped denim jeans, black shoes, a black Nike cap, and white headphones. She was carrying a large black handbag and another large dark bag was slung over her shoulder. She left Service SA at 1:05 pm. 8 Ms Rigney returned to Cash Converters and presented documentation obtained from Service SA, telling a Cash Converters employee she required the cash advance that day. The Cash Converters’ system lists the reason for Ms Rigney’s loan application as “for a family member’s funeral”. 9 Ms Rigney was required to apply for the loan on a tablet in Cash Converters, which involved providing her Centrelink and MyGov details, income and expenses, then nominating a bank account for payment of the advance and direct debit of repayments. Upon completing the application, a 4-digit SMS signing code was sent to Ms Rigney’s mobile phone by Cash Converters at 1:50 pm. Ms Rigney read the code to a Cash Converters employee and thereby finalised the cash advance contract at 1:52 pm, whereupon she received a cash advance of $200. Ms Rigney’s attendances at the Luis premises 10 Just after 2:00 pm on 7 December 2018, Chico Luis left his home, pulling shut and locking the front wooden door behind him, leaving Maria Luis at home with their dogs. He walked to the Kilburn RSL to meet up with friends. 11 Following Chico Luis’ departure, CCTV cameras located on a property across the road from and facing the Luis premises (“the CCTV cameras”) captured: 1. Ms Rigney walking east on Goodman Avenue at 3:36 pm, then into the front porch of the Luis premises, before going out of sight. The front door of the Luis house was accessed via the porch, comprising what appears to be a white framed window atop several courses of bricks. The western half of the -- 6 of 114 -- [2025] SASC 80 Bampton J 5 window is covered by what appears to be a screen precluding the CCTV cameras from capturing the front door. 2. Ms Rigney leaving the front porch of the Luis premises at 3:38 pm, walking down the driveway, then west on Goodman Avenue. As Ms Rigney walks away, she turns a supermarket trolley upside down on the footpath outside a property to the west of the Luis premises. 3. Ms Rigney walking east along Goodman Avenue at 4:50 pm towards the Luis premises, wearing a green T-shirt, denim shorts and white shoes, with a large black bag slung over her right shoulder and a black backpack on her back. She is captured retracing a few steps and stopping to remove the backpack, after which she places it over the fence and onto the front lawn of a property to the west of the Luis premises. 4. Ms Rigney entering the front porch of the Luis home at 4:51 pm and going out of sight. 5. A small dog exiting the front porch at 4:52 pm and briefly wandering around the front garden before apparently re-entering the front porch. 6. A small dog exiting the front porch at 4:53 pm and briefly wandering around the driveway before returning to the front porch area. 7. Ms Rigney exiting the front porch at 4:54 pm, briefly stopping in the driveway while appearing to look at the ground, then walking quickly down the driveway out of the Luis property, turning to her right and heading west on Goodman Avenue without retrieving the backpack she had deposited on the front lawn of the nearby property. 8. Darren Young, a friend of Maria and Chico Luis, who had been drinking with Chico Luis at the RSL, arriving at the Luis premises at 4:58 pm. He is captured going into the front porch and out of sight, returning to the driveway and appearing to attempt to open the large double gates across the driveway between the house and the eastern fence line. He can then be seen returning to the front porch, hurriedly leaving the front porch, jumping the double gates by climbing on a rubbish bin, going out of sight, jumping back over the double gates, returning to the front porch, exiting the front porch and running down the driveway, then west on Goodman Avenue. 9. Maria and Chico Luis’ grandson arriving at 5:04 pm in a vehicle driven by his mother. He can be seen entering the front porch, exiting, looking through the front windows of the house to the west of the front porch, checking the double gates, getting back into the vehicle, and being driven away. -- 7 of 114 -- [2025] SASC 80 Bampton J 6 The attempts to raise Maria Luis and Chico Luis’ return 12 Darren Young told police that when he attended the Luis premises at 4:58 pm, he saw one of Maria and Chico Luis’ dogs in the front yard, which was unusual. He knocked on the front door and yelled out to Maria Luis. As he did this, he heard groaning from inside the house and noticed blood on the porch. He said he knew something was wrong, so he jumped the double gates across the driveway and attempted to get into the house by the back door. As the back door was locked, he yelled out again to Maria Luis but could not hear anything in response. He went back to the front door and yelled “open the front door please”, whereupon he heard groaning again. As he was unable to gain entry, he texted a friend asking them to inform Chico Luis that something was wrong. He ran from the premises and enlisted the help of Jacquob Cronin to drive and collect Chico Luis, who had progressed from the Kilburn RSL to the Albion Hotel on Churchill Road. Jacquob Cronin picked up Chico Luis on George Street, which was around the corner from the Albion Hotel, and drove back to the Luis home. Chico Luis gained entry to his house using his key. 13 Upon entry, Chico Luis and Jacquob Cronin found Maria Luis lying on the living room floor covered in blood, but still alive. They attempted CPR. Darren Young, who had run back to the Luis home, called for an ambulance. Police officers arrived soon after followed by South Australian Ambulance Service (“SAAS”) and Medstar. Maria Luis was pronounced dead at 5:55 pm. Her death was caused by blood loss in conjunction with impaired breathing caused by stab wounds to her chest involving the lungs. 14 No person other than those detailed in [11] above was captured by the CCTV cameras attending the Luis premises on 7 December 2018 between Chico Luis’ departure and his return with Jacquob Cronin. Ms Rigney stabbed Maria Luis 15 Between going out of sight upon entering the Luis front porch at 4:51 pm and emerging minutes later, it appears Ms Rigney stabbed Maria Luis’ head, neck, and chest, resulting in 34 incised injuries assumed to be inflicted by a knife with a single cutting edge. A stab wound to Maria Luis’ left breast cut chest cage cartilage and would have been inflicted with moderate force. The remaining stab wounds would have been inflicted with mild force if inflicted with a sharp pointed knife with a cutting edge. The article used to stab Maria Luis has not been located. The arrest of Ms Rigney 16 When police attended Ms Rigney’s unit following Maria Luis’ death on 7 December 2018, she did not open the door. STAR Group officers arrived at 10:51 pm and forced entry, finding Ms Rigney asleep under a blanket in her bedroom with a plastic resealable bag containing a small amount of cannabis attached to her leg. Ms Rigney was arrested and charged with Maria Luis’ murder. -- 8 of 114 -- [2025] SASC 80 Bampton J 7 Ms Rigney’s police interviews on 7 and 8 December 2018 17 Ms Rigney was interviewed following her arrest on 7 December 2018, during which she appeared very drowsy and was slow to respond to police questions, causing the arresting officer to state that she appeared to be under the influence of alcohol, drugs or both (“the first police interview”). The pharmacologist Prof Jason White stated, having viewed the recording of the first police interview, that Ms Rigney appeared very drowsy, but was capable of responding and showed normal cognitive function. He suggested the drowsiness could have been caused by a drug or drugs, but said there was otherwise no evidence that she was under the influence of any drug. 18 During her second interview on 8 December 2018 (“the second police interview”), Ms Rigney appeared more lucid and engaged. Upon being told she did not have to answer any questions, Ms Rigney said: No she had someone inside her house and she had blood on the door and then I put my hand on the door I went inside she gave me a bag I came back outside and then the girl was screaming and then I just left. She repeated that she went: … to the [dealer’s] house and she had someone inside with her and then I asked for a bag so she let me inside she gave me a … fifty dollar bag and then she got stabbed in front of me and then I yeah I left. She told police, “[i]t looked like [she was stabbed with] a knife but it could have been anything”. She also said she only ever went into the first room of the house and that she only wanted a $50 bag, which she got. 19 Ms Rigney admitted having worn denim shorts and a T-shirt on the previous day and acknowledged owning a backpack consistent with the one deposited on the front lawn of a neighbouring property to the Luis premises. She said she was only at the Luis home for thirty seconds. Ms Rigney was asked by the interviewing officer whether she killed Maria Luis, and she said, “[n]o way bro”. She was then asked if she purchased any cannabis from Maria Luis, and the following exchange occurred: Ms Rigney: The bag you brang it in when we got arrested last night Interviewing officer: That’s not a fifty dollar bag that was a tiny little bit in it Ms Rigney: I smoked it I was straight up stoner bro that’s all I do is smoke weed man I feel sorry for this [girl’s] death but I […] I don’t know what to do about it 20 Ms Rigney also told police that Maria Luis was a dealer, that she purchased cannabis from her weekly, including in the week prior to the stabbing, and that she never had any conflict with her. She said when she first started going to buy cannabis, Maria Luis told her that she looked “a little bit too young maybe [she] -- 9 of 114 -- [2025] SASC 80 Bampton J 8 shouldn’t sell to [her]”. Ms Rigney said she responded, “honey I’ve got my ID with me I’ve got my age”. Ms Rigney said thereafter, Maria Luis did not mind selling to her. DNA analysis 21 DNA reference samples were obtained from a post-mortem blood sample from Maria Luis, and mouth swab kit samples from Chico Luis and Ms Rigney. These reference samples were compared with the DNA extracted from swabs of bloodlike staining on surfaces and items at the Luis premises, as well as on other items of evidence submitted by the crime scene investigators for analysis. 22 Analysis of the bloodlike stains found on one of Ms Rigney’s socks, the denim shorts she was wearing at the time of her arrest, a green “Stussy” T-shirt located on her bedroom floor, and her forehead, were all found to have a mixed DNA profile of three contributors. The results revealed a likelihood of greater than 100 billion to one for the proposition that Maria Luis had contributed DNA to the profile. 23 Police searched Ms Rigney’s premises and seized multiple knives secreted in the bedroom and lounge room, as well as a black handbag spattered with a bloodlike stain. Police also located recently burnt material in Ms Rigney’s yard. Swabs of the bloodlike stains on the handbag were found upon analysis to contain a mixed DNA profile of three contributors. The analysis revealed a likelihood of greater than 100 billion to one for the proposition that Maria Luis had contributed DNA to the profile. Ms Rigney’s personal circumstances and mental health history 24 Ms Rigney, who is Aboriginal, was born on 23 February 2000 and had a childhood marred by abuse and neglect. Her father had little contact with her and her siblings due to reported issues with violence, drugs, and alcohol. Ms Rigney’s mother was the subject of several notifications to child protection services arising from her intravenous drug use, mental health issues, neglect of her children, and placing the children at risk of violence, including by a man living in their home. 25 Between 2003 and 2005, Ms Rigney and her two siblings were subject to various short-term care and protection orders in Victoria and South Australia. In September 2005, the South Australian Department for Child Protection (“DCP”) placed the three children under the guardianship of the Minister until they reached the age of 18. Until 2016, Ms Rigney’s primary placement was with her maternal grandmother in Murray Bridge, supplemented by approximately 95 respite care placements in 21 households. She was subject to short-term, emergency, and residential care placements from October 2016. 26 Ms Rigney made a complaint to police in 2013 in respect of an alleged sexual assault committed against her in 2009. Police notes record that Ms Rigney’s identification of her alleged assailant was flawed. -- 10 of 114 -- [2025] SASC 80 Bampton J 9 27 In June 2017, whilst pregnant, Ms Rigney moved to the supported accommodation facility, Hannah Place, for minors under State guardianship who are pregnant or need parenting support. Ms Rigney gave birth to a son on 22 August 2017, fathered by her boyfriend. Her son was removed from her care at six weeks of age because of her mental instability. 28 Ms Rigney reported to the psychiatrists and psychologist who assessed her for the purposes of this matter that she was subject to sexual abuse, including rape, throughout her childhood. Ms Rigney’s admissions for mental health issues prior to 7 December 2018 29 From the age of 16, Ms Rigney had multiple admissions to mental health services. Ms Rigney’s medical records note that on 19 December 2016 at 2:00 am, she was arrested after having been missing for some months. She was subsequently released on bail but was left in the street when she refused to be collected by her DCP carer. Police then noticed her bashing an external door of the City Watchhouse and ranting incoherently. Police reported she was physically and verbally abusive, spitting at them, and running in front of traffic. Consequent upon this observed behaviour, Ms Rigney was taken to the Women’s and Children’s Hospital (“WCH”) under the care and control power prescribed by s 56 of the Mental Health Act 2009 (SA). 30 Ms Rigney was assessed at the WCH by a mental health nurse as presenting with no psychotic features, thought disorder or depression, and denying suicidal intent. It is recorded she was discharged into the care of the DCP and that no mental health input was deemed necessary at that point. 31 On 20 December 2016, Ms Rigney was admitted to the WCH Boylan Ward, a psychiatric inpatient facility for children and adolescents. It is recorded that she was admitted to the Boylan Ward under an inpatient treatment order (“ITO”) in the context of aggressive and disorganised behaviour at her emergency accommodation. She presented as irritable, sarcastic, and labile in mood. She remained in hospital for 24 hours for observation due to “some underlying paranoid themes and disorganisation of thoughts”. It is recorded that these symptoms did not persist in that she presented as organised in her thoughts, with conversation focused on her needs being met, and no evidence of any underlying psychotic illness or major mood disorder. It is also recorded that she remained belligerent and demanding throughout the admission, and that her behaviour could not be redirected or deescalated. The record refers to an incident where another patient told Ms Rigney to lower her voice, to which she responded by becoming agitated and charging at the patient, scratching his face. When staff tried to intervene, Ms Rigney punched a nurse in the abdomen. It is recorded that she has an enduring pattern of aggressive behaviour based on her impulsivity and distress intolerance, and that this behaviour may have been exacerbated by substance withdrawal, although it could not be confirmed as Ms Rigney refused to provide a urine sample. It is recorded that she was discharged into police custody and that -- 11 of 114 -- [2025] SASC 80 Bampton J 10 the benefits of future admissions would need to be evaluated and considered against the risk to herself and others. The WCH final separation summary records that she has a background of complex trauma and disorganised attachment, which manifests as recalcitrance and behaviour/emotional dysregulation. It is further recorded that these issues are exacerbated by substance use and a chaotic lifestyle. 32 On 27 January 2017, Ms Rigney was taken to the WCH by SAAS after being aggressive at home, having had an argument with her boyfriend, breaking a window, and being difficult to calm down. It is recorded that she was seven weeks’ pregnant. It is also recorded that she had directed abuse towards her carer, who reported that Ms Rigney had longstanding auditory hallucinations and possible psychotic episodes. Ms Rigney denied psychotic symptoms and insisted she had spoken openly to god and spirits for the majority of her teenage years. There was no evidence of cognitive impairment, and it is recorded that she “[appeared] to have reasonable insight yet poor judgement at times of any distress”. She was discharged into the care of a Hendercare carer. 33 On 22 March 2017, during an admission at the WCH, Ms Rigney assaulted a caseworker and the police were called. 34 On 6 May 2017, she was brought into the Flinders Medical Centre by police as she was expressing thoughts of self-harm when arrested. 35 In carer notes for 9 to 11 July 2017 contained in the WCH records, it is noted that Ms Rigney disclosed to staff at Hannah Place that she was seeing visions of the future and receiving messages from the dead. 36 On 11 July 2017, Ms Rigney was admitted to the WCH at 31 weeks pregnant. She presented as perplexed and hypervigilant, claiming that she could see visions of the future and receive messages from the dead, and that her music and abilities would change the world. She also described being able to see spirits and having a sense of being watched or followed, appearing fearful that her unborn baby could be harmed. Collateral information revealed that Ms Rigney’s mental state had abruptly changed over the preceding three days, and she admitted that she had been using up to a bag of cannabis per day but had been trying to cut down. It is recorded that these presenting symptoms were against a background of longstanding cannabis use, being away from her partner, living in new accommodation, and complex developmental trauma. She was detained under an ITO and admitted to the Boylan Ward. The following day she presented as calm and coherent without obvious psychotic symptoms. She indicated that she was willing to take medication and wished to be discharged from hospital. Accordingly, her ITO was revoked, follow-up was arranged with the Perinatal and Infant Mental Health Service, and a diagnosis of suspected drug-induced psychosis was made. 37 Ms Rigney’s son was born on 22 August 2017. It is recorded in the WCH separation summary following delivery that she demonstrated borderline and -- 12 of 114 -- [2025] SASC 80 Bampton J 11 antisocial personality traits, cannabis dependence, and complex developmental trauma. 38 On 30 August 2017, the day after her discharge from hospital following delivery of her son, Ms Rigney was again admitted to the Boylan Ward after having reported that spirits were raping her and that her child was dead. On the ward, she was calm and cooperative but spoke about spirits, her belief that they had entered her body, and her connections to the weather. She was administered depot risperidone. She attended court on 1 September 2017 in relation to a 42-day investigation and assessment order regarding her son, and was transferred to Helen Mayo House, a specialist unit at Glenside campus for mothers and babies, for ongoing care. 39 The WCH record for this admission includes the following: [Ms Rigney] was seen in July and admitted to Boylan Ward under level 1 ITO due to psychosis, which seemed to resolve fairly rapidly following admission and the commencement of risperidone 1mg. She has repeatedly missed appointments with Eastern CAMHS, where she was referred for follow up, and ultimately was closed to that service as she declined after not attending four scheduled appointments. She has been willing to engage with hospital based services but has a history of poor attendance at appointments. She continued to experience psychotic symptoms during her third trimester of pregnancy and post delivery. 40 Ms Rigney remained at Helen Mayo House from 1 September 2017 until 5 October 2017. She was again diagnosed with a drug-induced psychosis. It is recorded that her psychotic symptoms were slow to resolve, and she later acknowledged that she had been continuing to use cannabis whilst on the Glenside campus. With treatment and abstinence from cannabis, her mental state is reported to have improved. She demonstrated some warm, loving interactions with her son, but was unable to demonstrate sustained, safe, organised care or an ability to keep her son in mind, and she appeared preoccupied with her boyfriend. She was informed that her son would be placed in kinship care, and she was transferred to the Boylan Ward on 5 October 2017. She was discharged on 11 October 2017. The discharge summary records: Post delivery, [Ms Rigney’s] mental state worsened rapidly after she was discharged from hospital secondary to illicit drug use. She was admitted to Boylan [W]ard without her baby and subsequently admitted to Helen Mayo [H]ouse once a bed was available on the 1/9/17. Her symptoms were slow to improve and [Ms Rigney] kept using THC while she was on the ward which worsened her mental state. She was placed on an ITO but continued to leave the ward to use THC. Due to ongoing concerns about her capacity to care for [her son], DCP proceeded with an application for GOM 12. [Her son] was removed and therefore, [Ms Rigney] was transferred from Helen Mayo House to Boylan [W]ard for ongoing management. 41 Under the heading “assessment”, it is recorded that Ms Rigney had a resolving psychosis secondary to sustained drug use. It is recorded that this is against the background of significant childhood trauma, that she is very vulnerable to illicit drugs, and that her symptoms worsened every time she smoked cannabis. -- 13 of 114 -- [2025] SASC 80 Bampton J 12 She was discharged with Headspace follow-up and a plan to gradually taper her off oral risperidone once she returned to the community, while continuing to administer depot risperidone. 42 Ms Rigney was admitted to the Boylan Ward again from 21 February 2018 to 22 February 2018, having been detained on a level 1 ITO in Murray Bridge following an assault on her support worker at a bank. She was detained for management of suspected psychosis because of severe agitation, aggression and reported incoherent rambling. On admission, Ms Rigney evaded discussion of the events that led to her admission and acknowledged losing her temper but did not refer to the assault on her support worker. She denied any psychotic symptoms such as hallucinations or delusions. She was considered to have experienced a situational crisis with a violent outburst in the context of personality traits, which predispose her to poor frustration tolerance, impulsivity and risk-taking. In the absence of evidence of active psychosis, she was discharged from hospital. 43 Ms Rigney was taken to the Modbury Hospital by SAAS on 1 April 2018. The triage assessment records that she was agitated and teary, with disjointed conversation. She stated that she was sexually assaulted by 500 people, her vagina was hanging out, she was stabbed in the back with a needle, and she could not remember the last two days. It is recorded that she was visibly responding to internal auditory stimuli and that she discharged herself against advice. 44 Ms Rigney was admitted to the Lyell McEwin Hospital from 2 April 2018 to 5 April 2018 and diagnosed with drug-induced psychosis. The separation summary records that her behaviour in the emergency department became increasingly erratic, with her appearing to respond to internal stimuli and attempting to abscond, resulting in a code black. Her urine tested positive to cannabis, methamphetamine, and amphetamine. She was commenced on oral risperidone, placed under a level 1 ITO, and transferred to a psychiatric closed ward at the Lyell McEwin Hospital. It is recorded that she again reported being injected and raped but by day three of her admission, she had settled enough to warrant revocation of the ITO and was moved to an open ward. Following her discharge, it was recommended she have follow-up with community mental health and that she continue to take antipsychotic medication. The Lyell McEwin Hospital separation summary includes the following record: We suggest [Ms Rigney’s] significant development trauma has led to complex PTSD and personality vulnerabilities, where she tends to decompensate / experience dissociation or re-experience flashback at times of distress. Substance use can also lead to temporary psychosis. Despite [Ms Rigney] currently is stable and having low acute risk, considering her vulnerabilities, she is at chronic risk of misadventure, being abused by others and self harm. 45 On 14 May 2018, Ms Rigney presented to the Royal Adelaide Hospital (“RAH”) emergency department with a self-inflicted penetrating chest wound, which caused a haemopneumothorax. She was noted to be violent on the ward, requiring ongoing input from the RAH consult liaison psychiatry service, constant -- 14 of 114 -- [2025] SASC 80 Bampton J 13 one-to-one nursing and a security guard. She threatened physical violence towards staff on multiple occasions and attempted to hit a nurse, with a code black being called for behavioural disturbance. It is recorded she was poorly compliant with her medications, including by spitting out tablets. She was transferred to a psychiatric bed at Glenside Hospital on 8 June 2018 and discharged on 19 June 2018. Her primary diagnosis was drug-induced psychosis. She was noted to be guarded, argumentative, and irritable on the day prior to discharge but compliant with treatment. 46 On 2 September 2018, Ms Rigney was taken to the Queen Elizabeth Hospital (“QEH”) Crammond psychiatric unit after neighbours reported she had been wandering the streets topless and waving a knife. She is recorded as having been irritable and nonsensical at assessment and required management in the secure unit of the QEH for the first few days of her admission. Her diagnosis was again drug-induced psychosis, and she was given a loading dose of long-acting antipsychotic medication. She absconded from the ward on 18 September 2018, with her mental state earlier that day noted to have been less inhibited but still mildly euphoric. She was not seen to be hallucinating and denied any thoughts of self-harming or harming others. She was reported as a missing person after failing to return within 24 hours of absconding. 47 On 24 September 2018, Ms Rigney was found and returned to the QEH, where she expressed a delusional belief that she was pregnant and was subsequently readmitted to the Crammond psychiatric unit, remaining there until 17 October 2018. It is noted that she was difficult to interview, claimed her name was not right, and refused to engage with the clinicians. It is reported that she was angry, dismissive, paranoid, and yelled at staff and other patients. Her mental state gradually improved with treatment, which included her first dose of depot aripiprazole on 8 October 2018. She was placed under a level 1 community treatment order (“CTO”) on discharge, which included an order for the administration of depot aripiprazole every four weeks. 48 On 19 October 2018, Ms Rigney’s community mental health worker arranged for her to be brought into the QEH by police as she was not engaging in treatment, had ongoing delusions, and posed a risk to herself. She was not admitted. 49 During a visit to her Goodman Avenue unit by the community treating team (“treating team”) on 7 November 2018, the second depot aripiprazole was not administered as Ms Rigney refused to answer the door. A young woman was heard yelling abuse. Ms Rigney received the second depot aripiprazole on 8 November 2018. 50 Ms Rigney was detained by police on 12 November 2018 following an incident with her boyfriend during which she allegedly stabbed him. She was taken to the RAH emergency department by police on 13 November 2018, found to be uncooperative and considered fit for police custody. She was released later that day. -- 15 of 114 -- [2025] SASC 80 Bampton J 14 51 On 26 November 2018, Ms Rigney was uncooperative and did not engage with the treating team during an unplanned visit to her home. It is recorded she “exhibited intimidating, threatening, hostile and aggressive behaviour and terminated the [visit] by shutting the door”. 52 A level 2 CTO was granted on 28 November 2018. A home visit was attempted by the treating team on 6 December 2018 to administer the third depot aripiprazole. One member of the treating team knocked on the front door, called out, and heard music. Eventually, Ms Rigney’s boyfriend came to the door and said he would get her. After a few minutes, Ms Rigney appeared and shut the door firmly without a word. The treating team left and reported her non-compliance. 53 On 7 December 2018, the treating team again attended Ms Rigney’s home to administer the depot aripiprazole but there was no answer. Ms Rigney’s mental health history following her arrest 54 Ms Rigney’s third depot aripiprazole was administered on 9 December 2018 whilst she was in custody following the stabbing. 55 The following recitation of Ms Rigney’s psychiatric history between her arrest on 7 December 2018 and September 2021 is taken from the forensic psychiatrist, Dr Paul Furst’s report dated 2 May 2022: Ms Rigney was admitted to the Adelaide Women’s Prison on 10/12/2018 and the admitting nurse noted that she was difficult to assess, but the medical officer the following day found her only mildly uncooperative and to have normal thought content. She was reviewed on 12/12/2018 by Dr Cassie Smith, then a senior forensic psychiatry registrar, who noted that she did not know Ms Rigney, nor with what she had been charged. Ms Rigney was not willing to speak but was observed to “laugh incongruently” and appeared to be responding to internal stimuli when looking into the distance. She was noted to be paranoid and had a fatuous affect. A nursing entry on 17/12/2018 noted that she engaged poorly and provided “inappropriate answers to questions” and was “laughing inappropriately” and appeared to be reacting to internal stimuli. Another nursing entry on 20/12/[2018] noted that she was aggressive and unwilling to talk and later that day it was noted that Department for Correctional Services staff reported “unusual/psychotic behaviour in outside recreation area” and by 2100hrs that day she had been moved to D Wing (maximum security). She was threatening and abusive to nursing staff on 23/12/2018. She was reviewed by the visiting medical officer on 24/12/2018 and it was noted that she was laughing inappropriately and the content of her speech was [difficult] to follow (suggesting a disorder of thought form) and she expressed paranoid ideas. She was also observed to respond to internal stimuli with impaired insight and judgement. Ms Rigney was reviewed by Dr Megan Ferris on 03/01/2019. Dr Ferris noted that Ms Rigney was guarded about why she had been [moved] to D Wing and claimed to have no problems, but poor sleep and that she was not getting enough food. She claimed that she had been “nice and calm” and denied being irritable or aggressive. Dr Ferris noted that Ms Rigney was fatuous with frequent unwarranted giggling and intense eye contact at times and at times she appeared to be responding to internal stimuli, despite her denial of hearing auditory hallucinations. Dr Ferris assessed her as likely to have psychotic symptoms, -- 16 of 114 -- [2025] SASC 80 Bampton J 15 increased her dose of antipsychotic medication and requested collateral information from Headspace. Nursing staff reviewed her mental state on 12/01/2019 and noted that she was intimidating and believed herself to be pregnant and that she could feel the baby kicking despite having a negative pregnancy test. She demanded an ultrasound test to look for pregnancy. She maintained the same delusional belief the next day and again claimed that she could feel a baby kicking. On 21/01/2019 she was noted to be labile and giggly, naïve to her situation and claimed she suffered from multiple personalities. She was seen again by Dr Smith on 30/01/2019. She was noted to be highly irritable and aggressive in her responses, was guarded and appeared to be responding to internal stimuli. Dr Ferris (07/02/2019) saw her again in A wing and again noted that she was irritable and guarded when questioned. Dr Ferris changed her medication. A nursing entry from 11/02/2019 noted that she remained “aloof and disorganised” with some inappropriate laughter. By 28/02/2019 when seen again by Dr Ferris, she was thought to have shown some improvement in her mental state. A nursing entry on 04/03/2019 noted that she reported believing that there was “a spider living in [her] bottom” and that she could not sleep because she was checking the bed for spiders at night. She was reportedly quite fixated on this and would not accept reassurance from nursing staff. She saw Dr Ferris again on 14/03/2019. Dr Ferris noted that she was much less irritable and verbally abusive, but she was still “slightly paranoid”. She continued to report delusional beliefs about spiders to nursing staff on 26/03/2018 and 01/04/2019 and to Dr Ferris on 04/04/2019. By that time Dr Ferris believed her to be suffering from Schizophrenia and that she had shown some response to the prescription of antipsychotic medication. When reviewed by Dr Ferris on 15/08/2019 Ms Rigney requested a mood stabiliser to help with the “diseases in [her] head” and reported that her mood was all muddled up, she had difficulty attending to her education classes and whilst she denied ever having hallucinations, she was observed to be responding to internal stimuli during her interview and was paranoid about what Dr Ferris was writing in her notes. Dr Ferris noted that Ms Rigney was on the waiting list for James Nash House and that nursing staff reported that she had reported having a spider in her rectum, had been caught smoking a tampon, expressed numerous unfounded somatic complaints and talked about spiders and bugs and that she thought she had HIV. Dr Ferris noted that Ms Rigney’s condition had not responded to trials of aripiprazole, risperidone or paliperidone and therefore warranted a trial of clozapine (the gold standard treatment for Schizophrenia that does not respond to other agents) but that an inpatient admission would be required to start the treatment. She continued to express delusional beliefs about a spider in her rectum when reviewed again on 05/09/2019. On 15/10/2019 she told a nurse that she believed that the other prisoners had taken a ‘hit’ out on her and she had heard them threatening to ‘rip her cervix out’. She repeated this claim to Dr Condon (Senior Psychiatry Registrar) on 16/10/2019 who assessed Ms Rigney to have schizophrenia with ongoing symptoms and to be in need [of] urgent admission to James Nash House. On 22/10/2019 she was transferred to James Nash House. She was admitted to James Nash House on 22/10/2019. The separation summary noted that she had multiple previous presentations to ED and admissions to psychiatric units with episodes of erratic, disorganised and aggressive behaviour associated with visual hallucinations and somatic and paranoid delusions. There had been previous reports of thought disorder and delusional beliefs included that she had been injected and raped by 500 men and therefore needed a new vagina and rectum as [her’s] were ‘hanging out’ due to the rapes. She had expressed delusions that she could control the weather through her -- 17 of 114 -- [2025] SASC 80 Bampton J 16 emotions, that she was a God or that she was part of the Illuminati. She felt that she had been constantly watched and that she was possessed by a demon and that her parents were not her real parents. She had previously expressed delusions of having a spirit jumping in and out of her, raping her and strangling her unborn son, as well as vision of her partner joining the army and dying as a result. On her initial assessment in James Nash House she [was] initially guarded, but reported seeing and hearing ghosts and was fearful of being alone and showering at night. At times she was bizarre in her behaviour and she had … the physical workup required to initiate clozapine. Clozapine was started and titrated up to the therapeutic dose before being discharged back to the Adelaide Women’s Prison on 31/12/2019. She was readmitted to James Nash House on 11/12/2020 until 25/03/2021. This admission was precipitated by worsening auditory and visual hallucinations prompting Dr Ferris to place her under a Level 1 ITO. On the ward she appeared polite and cooperative and reported auditory and visual hallucinations and delusions about a lady who could see stars almost all of the time. She had poor insight into her illness and required 1:1 nursing. She was difficult to engage on ward and reported that talking about her illness made it worse but reported ongoing auditory hallucinations and various somatic complaints. Her medications (depot zuclopenthixol and oral clozapine) were optimised, but by the time of her discharge she reported that there had been no change in her psychotic symptoms and she was not engaging with the treating team and therefore it was decided that she would be discharged back to the Adelaide Women’s Prison. Interestingly, a CBIS entry dated 18/03/2021indicates that she reported having auditory hallucinations that become worse when she talks about them, ghosts who she saw at the edge of her bed, one who stroked her hair and a female ghost that walked the corridors at night. She reported that she was worried that they would scratch her and said that one [had] tried to rape her in the shower four days earlier, in keeping with her report of groin pain at the time. Nursing staff had reported that she was talking to herself at night and had been verbally aggressive to staff and other patients. Her CBIS records indicate that she was readmitted to James Nash House on 20/04/2021 due to a deterioration in her mental state. An entry from 18/09/2021 details her mental state and noted that she was appropriate in her behaviour with others with some underlying irritability and she denied having auditory hallucinations and had not been observed responding to internal stimuli. Fitness to plead and mental competence 56 Ms Rigney was committed for trial in this Court on the charge of murder. She was not arraigned on her first appearance on 3 February 2020 as her counsel informed the Court of concerns regarding her fitness to stand trial and mental competence to commit the offence. 57 Thereafter, many reports were prepared concerning Ms Rigney’s fitness to plead and whether the mental incompetence defence was available to her pursuant to s 269C of the CLCA (“the s 269C defence”). “A tiger by the tail”1 58 In his first report dated 26 March 2020, which had been requested by Ms Rigney’s solicitors, the forensic psychiatrist Dr Narain Nambiar considered Ms Rigney was unfit to plead and that the s 269C defence was available to her. 1 The description used by Kelly J during a directions hearing on 28 August 2020. -- 18 of 114 -- [2025] SASC 80 Bampton J 17 However, he altered his opinion in his report dated 20 July 2020, concluding that she was fit to stand trial and the s 269C defence was not available to her. He remained of the view that Ms Rigney was fit to stand trial in his report dated 8 February 2021. 59 In Court-ordered reports dated 21 August 2020 and 20 September 2020, the psychiatrist Dr Megan Ferris considered Ms Rigney was unfit to stand trial and that the s 269C defence was available to her. Dr Ferris considered Ms Rigney was fit to stand trial in her report dated 23 March 2021, but remained of the opinion that the s 269C defence was available to her. 60 There then followed a period in which Ms Rigney’s psychiatric condition deteriorated such that both Dr Nambiar and Dr Ferris were unconvinced of her fitness to stand trial, and the May 2021 trial listing was vacated. 61 In his report dated 26 July 2021, Dr Nambiar determined that Ms Rigney’s condition had improved and that while she was fit to stand trial, she should remain at James Nash House (“JNH”) for the duration of the trial. 62 In her report dated 26 July 2021, Dr Ferris similarly considered Ms Rigney was fit to stand trial. Dr Ferris also took the opportunity, in assessing Ms Rigney’s fitness, to reassess her mental competence at the time of the stabbing. Dr Ferris reported that having done so, she no longer considered the s 269C defence was available to Ms Rigney. 63 In a Court-ordered report dated 2 May 2022, Dr Furst reported that Ms Rigney was fit to stand trial and the s 269C defence was not available to her. 64 A further trial listing in June 2022 was vacated to accommodate counsel availability. 65 Just prior to the commencement of the adjourned trial on 8 September 2022, Ms Rigney’s solicitors served reports they had requested from the psychologist, Prof Ian Coyle and the psychiatrist, Prof Phillip Morris, both of whom reported Ms Rigney was fit to stand trial and the s 269C defence was available to her. 66 The following table records the key findings in the reports of Dr Nambiar, Dr Ferris, Dr Furst, Prof Coyle, and Prof Morris received into evidence: Date Author Opinions 26 March 2020 Dr Nambiar Unfit & Incompetent 20 July 2020 Dr Nambiar Fit & Not Incompetent 21 August 2020 Dr Ferris Unfit & Incompetent 20 September 2020 Dr Ferris Unfit & Incompetent -- 19 of 114 -- [2025] SASC 80 Bampton J 18 Date Author Opinions 8 February 2021 Dr Nambiar Fit 23 March 2021 Dr Ferris Fit & Incompetent 19 April 2021 Dr Lowe and Dr Ferris Psychiatric progress update 28 April 2021 Dr Nambiar Questions Fitness 30 April 2021 Dr Ferris Unfit 26 July 2021 Dr Nambiar Fit but remain in JNH for trial 26 July 2021 Dr Ferris Fit & Not Incompetent 2 May 2022 Dr Furst Fit & Not Incompetent 28 July 2022 Prof Coyle Fit & Incompetent 10 August 2022 Dr Nambiar Response to Prof Coyle’s report dated 28 July 2022 15 August 2022 Dr Ferris Response to Prof Coyle’s report dated 28 July 2022 22 August 2022 Prof Morris Fit & Incompetent 22 August 2022 Dr Furst Response to Prof Coyle’s report dated 28 July 2022 28 August 2022 Prof Morris Incompetent 29 August 2022 Dr Ferris Response to Prof Morris’ report dated 22 August 2022 The trial pursuant to s 269G of the CLCA 67 Ms Rigney elected to be tried by judge alone and the matter proceeded by way of examination under Part 8A of the CLCA (“Part 8A”) into Ms Rigney’s mental competence to commit the offence of murder. 68 On 8 September 2022, Ms Rigney was arraigned and pleaded not guilty to the charge of murder. I then made an order under s 269E(2) that the matter proceed first with the trial of the objective elements of murder pursuant to s 269G A. 69 On 12 September 2022, pursuant to s 269G A(1), I heard evidence and representations put by the prosecution and the defence relevant to whether the objective elements of murder were established against Ms Rigney. I found the objective elements of murder were established beyond reasonable doubt and -- 20 of 114 -- [2025] SASC 80 Bampton J 19 recorded a finding to that effect pursuant to s 269G A(2). The trial then proceeded as a trial of Ms Rigney’s mental competence to commit murder pursuant to s 269G B. The test for mental competence 70 The s 269C defence is as follows: 269C—Mental competence (1) A person is mentally incompetent to commit an offence if, at the time of the conduct alleged to give rise to the offence, the person is suffering from a mental impairment and, in consequence of the mental impairment— (a) does not know the nature and quality of the conduct; or (b) does not know that the conduct is wrong; that is, the person could not reason about whether the conduct, as perceived by reasonable people, is wrong; or Note— Paragraph (b) adopts the test as stated and excludes from consideration whether the defendant could reason with a moderate degree of sense and composure as set out in R v Porter (1936) 55 CLR 182. (c) is totally unable to control the conduct. (2) If, on an investigation under this Division, a person is found to be mentally incompetent to commit an offence and the trial judge is satisfied, on the balance of probabilities, that the mental impairment at the time of the conduct alleged to give rise to the offence was substantially caused by self-induced intoxication (whether the intoxication occurred at the time of the relevant conduct or at any other time before the relevant conduct), the person may not be dealt with under this Part but may (if appropriate) be dealt with under Part 8. (3) However, despite the fact that the judge is satisfied that the person's mental impairment at the time of the conduct alleged to give rise to the offence was substantially caused by self-induced intoxication, the judge may nevertheless make an order that the person be dealt with under this Part after taking into account— (a) the time and circumstances of when and how the intoxication caused the mental impairment; and (b) the interests of justice; and (c) whether the making of such an order would affect public confidence in the administration of justice. 71 A “mental impairment” is defined in s 269A(1) of the CLCA and includes a “mental illness”, an “intellectual disability”, and a “disability or impairment of the mind resulting from senility”. A “mental illness” is defined as a “pathological infirmity of the mind (including a temporary one of short duration)” with a footnote explaining that: -- 21 of 114 -- [2025] SASC 80 Bampton J 20 A condition that results from the reaction of a healthy mind to extraordinary external stimuli is not a mental illness, although such a condition may be evidence of mental illness if it involves some abnormality and is prone to recur (see R v Falconer (1990) 171 CLR 30). 72 The definition of “mental impairment” under s 269A(1) of the CLCA does not include “intoxication”, which is defined as “a temporary disorder, abnormality or impairment of the mind that results from the consumption or administration of a drug”. Intoxication excluded 73 Samples were obtained from Ms Rigney during forensic procedures conducted following her arrest. Analysis indicated that her blood sample contained: • approximately 0.01 g methylamphetamine; • approximately 0.078 mg/L aripiprazole; • 0.007 g/L THC; and • 0.058 mg 11-nor-9-carboxy-Δ9-THC. The urine sample contained: • methylamphetamine; • amphetamine; • aripiprazole; • paliperidone; • nordiazepam; • temazepam; and • 11-nor-9-carboxy-THC. 74 Prof White interpreted the results of the analysis of Ms Rigney’s blood and urine and noted the following: 1. The antipsychotic medication aripiprazole was detected in the blood and urine samples, while the antipsychotic paliperidone was detected only in the urine sample. 2. The concentration of aripiprazole in the blood sample was relatively low, but consistent with normal therapeutic use. It was consistent with a dose in the range of 10 to 15 mg/day, assuming Ms Rigney’s last use of aripiprazole occurred many hours prior to the blood sample collection. It is also consistent -- 22 of 114 -- [2025] SASC 80 Bampton J 21 with administration of the drug by monthly injections, although slightly below the low end of the expected range. 3. The paliperidone in the urine sample could be attributable to either consumption of paliperidone itself or to the metabolism of risperidone. Both paliperidone and risperidone are prescription antipsychotic drugs. 4. Risperidone was not detected in the blood sample. 75 Prof White concluded: 1. Ms Rigney most likely consumed cannabis after the stabbing. He could therefore not comment on any effects of cannabis on her at the time of the stabbing. 2. Ms Rigney most likely consumed methylamphetamine at least one day prior to the stabbing. 3. It is possible that at the time of the stabbing, Ms Rigney was experiencing persistent or rebound effects of methylamphetamine including fatigue, insomnia, and psychosis after the main effects had diminished. If she were experiencing any effects, they were likely not pronounced. 4. Aripiprazole would be expected to reduce the likelihood of psychotic symptoms resulting from the combination of cannabis and methylamphetamine. Ms Rigney experiencing psychotic symptoms due to the combination of cannabis and methylamphetamine at the time of the stabbing therefore seems unlikely. 5. Ms Rigney would have been experiencing therapeutic effects of aripiprazole, but no significant effect of the antipsychotics paliperidone or risperidone at the time of the stabbing. 76 Prof White also observed that Ms Rigney did not appear drug-affected in the CCTV footage as detailed above prior to the stabbing. 77 As I have already stated, Prof White noted, by reference to the video recording of the first police interview, that from her arrest on 7 December 2018 until 12:52 am the next day, Ms Rigney appeared very drowsy but was capable of responding and showed normal cognitive function. He suggested the drowsiness could have been caused by a drug or drugs, but that there was otherwise no evidence that she was under the influence of any drug. 78 Both the prosecution and defence submit the weight of evidence indicates that Ms Rigney was not materially affected by drugs at the time of the stabbing. -- 23 of 114 -- [2025] SASC 80 Bampton J 22 Ms Rigney’s mental impairment 79 There is no dispute that at the time of the stabbing, Ms Rigney had a mental impairment as defined by s269A; namely, treatment-resistant schizophrenia. The question is whether Ms Rigney’s mental impairment caused her to be mentally incompetent to commit the murder of Maria Luis pursuant to s 269C. 80 As mental competence is presumed pursuant to s 269D, the burden falls on the defence to establish on the balance of probabilities that at the time of the stabbing, Ms Rigney had a mental impairment that affected her in at least one of the ways set out in s 269C(1). 81 Section 269G B(3) prescribes what I must do at the conclusion of this trial: (3) At the conclusion of the trial of the defendant's mental competence, the court must decide whether it has been established, on the balance of probabilities, that the defendant was at the time of the alleged offence mentally incompetent to commit the offence and— (a) if so—must declare that the defendant was mentally incompetent to commit the offence, find the defendant not guilty of the offence, and (subject to Division 3A) declare the defendant to be liable to supervision under Division 4 Subdivision 2; (b) if not—must record a finding that the presumption of mental competence has not been displaced and proceed with the trial in the normal way. 82 The prosecution says that the presumption of mental competence prescribed by s 269D has not been displaced and that Ms Rigney engaged in the conduct that killed Maria Luis in a heightened emotional state without being psychotically driven. The defence does not rely on s 269C(1)(a) but says that because of her mental impairment, Ms Rigney did not know that her conduct was wrong pursuant to s 269C(1)(b) and/or was totally unable to control her conduct pursuant to s 269C(1)(c). 83 The 11-day trial was heard over many months to accommodate the availability of the experts, counsel, and the Court. The trial also accommodated Ms Rigney’s need, identified by her treating psychiatrists, for a 15-minute adjournment every 45 minutes. 84 Ms Rigney called Prof Coyle and Prof Morris to give evidence, while the prosecution called Brevet Sergeant McKenzie (a crime scene investigator), Dr Nambiar, Dr Ferris, and Dr Furst. 85 Whilst Prof Coyle and Prof Morris gave evidence prior to the experts called by the prosecution, I will begin by discussing the opinions of Dr Nambiar, Dr Ferris, and Dr Furst as they assessed Ms Rigney before Prof Coyle and Prof Morris. -- 24 of 114 -- [2025] SASC 80 Bampton J 23 Dr Nambiar 86 Dr Nambiar obtained his specialist qualifications in 1997 and has been the clinical director of JNH since 2015. Dr Nambiar gave evidence he also has a part-time private practice and has 30 years’ experience in providing expert opinions on the question of competency to commit offences and fitness to stand trial. Dr Nambiar’s report dated 26 March 2020 87 Ms Rigney’s solicitors obtained a report from Dr Nambiar dated 26 March 2020. 88 Dr Nambiar reported that Ms Rigney’s standard response to questioning during his first assessment of her was “I can’t remember”, but with prompting, he was able to obtain the following account of events leading up to the stabbing: 1. She had been using amphetamines at least weekly prior to 7 December 2018; 2. She had also been using cannabis regularly, having obtained it from different people including Maria Luis. She smoked bongs on 7 December 2018; 3. She recalled using methamphetamine approximately one week before 7 December 2018; 4. She had very little recollection of how she was feeling around the time of 7 December 2018. In his first report, Dr Nambiar referred to the treating team notes, which record that she had been irritable and abusive towards them when they who visited her at her home; 5. When asked whether she heard voices, she said she could not remember but also told Dr Nambiar she had heard voices in the past that tell her what to do, although never to stab or otherwise hurt anybody; 6. She did not recall attending Service SA. While she recalled going to Cash Converters and obtaining money, she had poor recollection of what she spent the money on; 7. She had no recollection of the rest of 7 December 2018 apart from smoking cannabis and listening to music in her house; and 8. She said she had no contact with Maria Luis other than occasionally buying cannabis from her. She recalled walking to her home and buying it on at least two occasions in the past. She also said she had a group of friends who would buy cannabis for her, including from Maria Luis. She was adamant she did not buy methamphetamine from Maria Luis and that she had never had any verbal or physical altercations with her. -- 25 of 114 -- [2025] SASC 80 Bampton J 24 89 Dr Nambiar’s opinion following two hour-long interviews with Ms Rigney and review of the documentation provided to him – which did not include the video of the second police interview – was that her fitness to stand trial remained in question. He reported, “based on how she presented when she was incarcerated shortly after her arrest, it is pretty evident [Ms Rigney] was experiencing acute disorganised thought, was irritable and that her thought processes were impaired. In my opinion this was due to her schizophrenia in combination with the possible effects of previous substance abuse”. 90 Dr Nambiar stated Ms Rigney had a diagnosis of schizophrenia and that in the days and weeks leading up to the stabbing, her mental state was unstable despite changes in her medication, and that her use of cannabis and amphetamines further exacerbated her condition. He said she was exhibiting ongoing acute and chronic symptoms of schizophrenia, including irritability, aggression, and delusions, in the weeks and months prior to the stabbing. 91 Having applied the test for mental competence, Dr Nambiar concluded Ms Rigney knew the nature and quality of her conduct. He stated her inability to recall all of the details appeared to be evasive, “perhaps in order to naturally deny allegations”, and the issue of whether she knew her conduct was wrong as perceived by reasonable people remained difficult to determine. 92 Dr Nambiar noted that the facts of charge recorded that Ms Rigney told police she had entered the Luis house to buy cannabis and that there were other people responsible for the stabbing. 93 He summarised his opinion as follows: It is clearly up to the Court to decide the objective elements of the offence however, it is my opinion that your client’s inability to remember what had occurred are in part keeping with defensive behaviour whilst on the other hand, her motive to commit the offence remains uncertain and on the balance of probabilities, may in fact have been in the context of delusional thinking. The number of stab wounds would indicate significant anger or some other emotion that may have its origins in delusional thought, or unstable mood. It is also unclear as to whether your client’s ability to control her conduct was maintained as a result of her mental state at the time. In my opinion, on the balance of probabilities, it is my view that more likely than not your client’s mental processes were that impaired that she was unable to know that her conduct was wrong and was more than likely responding to disordered thought processes and therefore has a mental impairment defence available to her. Dr Nambiar’s report dated 20 July 2020 94 Dr Nambiar provided an addendum report dated 20 July 2020 in response to the Court’s order pursuant to ss 269WA(1)(a) and (b).2 In the second report, 2 Sections 269WA(1) and (2) of the CLCA prescribe the Court’s power to order examination of the defendant by a psychiatrist and require that the results of the examination be reported to the Court. -- 26 of 114 -- [2025] SASC 80 Bampton J 25 Dr Nambiar considered a letter from the Director of Public Prosecutions dated 26 June 2020 seeking his further comment on certain matters and propositions (“the DPP letter”), along with the video of the second police interview. 95 Dr Nambiar also re-interviewed Ms Rigney for approximately one hour. Dr Nambiar reported that Ms Rigney’s schizophrenia symptoms had continued to resolve over time with treatment, and her mental processes at the time of his second report were not so disordered or impaired that she was unfit to stand trial. He further considered that Ms Rigney’s appearance, conduct, and in particular, conversation during the second police interview3 was not consistent with psychosis. Specifically, he reported she did not appear to be thought disordered or expressing delusional ideas in relation to the stabbing or Maria Luis. He noted that she provided an exculpatory account. 96 Dr Nambiar considered Ms Rigney’s lack of symptoms during the second police interview could be consistent with her experiencing lucid thoughts and the effects of intoxication having worn off. His opinion was that the degree of composure demonstrated by Ms Rigney during the second police interview made it less likely that she was acutely psychotic at the time of the stabbing. This presentation, according to Dr Nambiar, in the absence of any obvious delusional thinking or hallucinatory phenomena, gave more weight to a conclusion that she knew her conduct was wrong. Dr Nambiar’s report dated 8 February 2021 97 In his report dated 8 February 2021 concerning fitness to stand trial, Dr Nambiar stated: I put it to her that when she was interviewed by SAPOL, the recording of which I had viewed on DVD, that she had provided a number of explanations of what had occurred at the victim’s house when she was present, that may have given rise to the victim’s death. She denied having any memory of this and made reference to attending the house to buy marijuana but had no other recollection of anything else that occurred that day. When I went through the account of the days leading up to and the day of the offence that she had provided to me when I had interviewed her in 2020, she now claims no recollection. I noted that her level of co-operation and motivation to address any questions to her with regards to the offence that she has been charged with, was extremely limited and it gave me the impression that she was avoiding answering questions. ... Ms Rigney appears to have a relatively intact memory with regards to incidents that have occurred in her past that she chooses to raise or focus on. There does not appear to be a generalised inability to recall details of past events. Her current inability to recall the events of the day of the offence is in contrast to her ability to recall some details when I interviewed her in 2020. This inability is not due to an impairment. 3 Dr Nambiar referred to this interview as having taken place between 2:00 and 3:00 am on 8 December 2018. However, the second police interview commenced at 2:45 pm. -- 27 of 114 -- [2025] SASC 80 Bampton J 26 I would also add that although she claimed on her most recent interviews with me during her current admission to James Nash House that she has no recollection, I note that in my first interview with her at the Adelaide Womens Prison in March 2020, her memory of events and version of events were much more detailed and she was able to describe those details with much conviction as compared to the effort she appears to be making now. In my opinion, her mental state has improved considerably since March of 2020 and since I subsequently [interviewed her] in July 2020. Her mental state now is much more stable and sustained. In my opinion, her willingness to co-operate is the more overriding factor at the present time. (Emphasis added) 98 Dr Nambiar concluded on that basis Ms Rigney was fit to stand trial. Dr Nambiar’s report dated 28 April 2021 99 In his report dated 28 April 2021 providing an update regarding Ms Rigney’s fitness to stand trial pursuant to s 269K, Dr Nambiar reported: As referred to in my previous report, she can be drawn into conversations that she chooses to and during those periods, her thought processes do not appear to be impaired by psychotic experiences. There appears to have been a significant improvement with medication (I note there have been changes to her anti-psychotic regime) and yet her illness continues to demonstrate features of a treatment resistant form of Schizophrenia. The term ‘Treatment Resistant’ means that despite medications taken regularly and supervised, she continues to have chronic residual symptoms that consist of delusions and hallucinations. I continue to maintain however, that her ability to concentrate is quite variable but appears to be, in my view, more related to her motivation to co-operate, rather than an impairment of concentration brought about by her illness. What did concern me during this interview however, appears to be her level of sedation which would impair her ability to remain reactive and attend and concentrate during the course of the proceedings. Given the fact that Ms Rigney’s mental state appears to fluctuate both during the course of an interview and in fact when there is a change in environment, and that she appears to be better functioning when in hospital, I have recommended that she remain in James Nash House now, up until and during the period of her trial. This would give her the best opportunity to participate in a meaningful way without the added burden of a fairly hostile and unpredictable environment in prison. I also feel that her medications need to be adjusted again in order to bring about a more favourable response to medication which will allow me to arrive at a definite opinion regarding to what extend her illness will impact on her ability to participate in court. Although I feel that her motivation to co-operate is of her own volition, I would like to be certain that this is the case and to exclude the impact that her illness has on her ability to participate in her trial in a meaningful way. (Emphasis added) -- 28 of 114 -- [2025] SASC 80 Bampton J 27 100 Accordingly, Dr Nambiar suggested the trial listed to commence on 6 May 2021 be postponed while Ms Rigney remained in JNH “in order to make the necessary adjustments to her medication and for regular evaluations to occur by [himself] and Dr Ferris to arrive at a firm opinion regarding her fitness to stand trial”. Dr Nambiar’s report dated 26 July 2021 101 In his report dated 26 July 2021, Dr Nambiar said that following assessment of Ms Rigney, he considered she was fit to stand trial. Dr Nambiar remained of the view Ms Rigney should remain in JNH for the duration of her trial to provide her with hospital support and maintain her compliance with treatment, thereby giving her the best chance of participating in the proceedings. Dr Nambiar’s evidence 102 Dr Nambiar was asked in evidence to detail the factors he considered in reaching his altered opinion as detailed in his second report. He said it was about linking Ms Rigney’s illness to her behaviour at the time of the stabbing. He noted she has an established diagnosis of schizophrenia, along with a history of personality disorder, quite disruptive behaviour, and quite violent behaviour including using weapons. He said her behaviour at times can be erratic, impulsive and quite bizarre in response to her thinking. However, Dr Nambiar said that having read the evidence and interviewed her, he found it difficult to make a connection between her active schizophrenia symptoms of delusions and hallucinations and the stabbing. 103 Dr Nambiar said the hallucinations Ms Rigney experienced were a combination of auditory and visual, as well as hallucinations of touch and feel. For example, she reported feeling that her sexual organs were hanging out of her body. Dr Nambiar also said Ms Rigney had several delusions, including that she was being injected with a needle, that she was raped, that she needed a new vagina and rectum, and that she had the power to control weather with her mood, such as lightning. She also had the belief that she was a part of the Illuminati, that she is God, and that she could predict and change world events like natural disasters. 104 Dr Nambiar explained that a command hallucination is an auditory hallucination of a voice telling a person to do something. He said it is usually a repetitive voice that the person finds very difficult to ignore and resist. Dr Nambiar said that, on interviewing Ms Rigney, she reported hearing voices, but that they never commanded her to harm anyone. Dr Nambiar said it does not necessarily follow that a person experiencing a command hallucination would not appreciate whether the voice was telling them to do the wrong thing. 105 Dr Nambiar explained a personality disorder develops in a person’s formative years. He said Ms Rigney has a personality disorder that is characterised by both borderline and antisocial traits. He described the borderline traits as pervasive instability. He explained that when a child is developing, they are -- 29 of 114 -- [2025] SASC 80 Bampton J 28 responsive to their emotions and impulsive, but that as they experience life and interact with others, they learn to curb those behaviours. However, this refinement does not occur when a person has a borderline personality disorder (“BPD”), which results in constant instability that can affect the intensity and stability of the person’s relationships. 106 Dr Nambiar noted that Ms Rigney’s developmental years were affected by traumatic experiences and instability in her environment. He said, additionally, she has some antisocial traits which include deceitfulness, impulsivity, difficulty controlling her anger, and a disregard for rules. Dr Nambiar explained that a personality disorder is not a mental illness, and it does not constitute a mental impairment. However, in terms of examining Ms Rigney’s actions and how she conducts herself, her personality disorder needs to be factored in as well as the superimposed schizophrenia. 107 Dr Nambiar said the fact that Ms Rigney was one day overdue for her aripiprazole depot injection at the time of the stabbing would not have had any significant effect. He explained that the way the antipsychotic injection is administered results in a peak of level and by the time the peak starts to drop, another dose is given. He explained that the aim is to give the drug regularly such that eventually, the peak remains constant. He said if administration of a dose were a day late, the level may have dropped slightly but not significantly. Dr Nambiar said that, at the time of the stabbing, Ms Rigney’s aripiprazole level should have reached a steady state and would not yet have dropped to a subtherapeutic level. Dr Nambiar said he would expect the therapeutic effect of the drug to be lost if a dose had not been administered for a period of a few weeks. 108 In preparing his second report, Dr Nambiar said he considered the video of the second police interview, the DPP letter, and his further interview with Ms Rigney. 109 He said the video of the second police interview, which he did not have at the time of his first report, caused him to change his opinion as to Ms Rigney’s competence. He explained that the first stage in determining whether someone has a s 269C defence is to consider whether there is a mental impairment, which Dr Nambiar noted was not in dispute in this matter. He said one then needs to consider ss 269C(1)(a), (b), and (c), and that in order to do so, it is necessary to ascertain the person’s mental state at the time of the alleged criminal conduct or as close to that time as possible. 110 Dr Nambiar explained he was looking at whether there was a delusional motive or whether Ms Rigney committed the stabbing because of either a command hallucination or some other symptom of her illness. He said that while it was difficult to pin that down during his first interview, there was overwhelming evidence that Ms Rigney had schizophrenia. In those circumstances, and given the fact that he had not seen the video of the second police interview, he gave her the -- 30 of 114 -- [2025] SASC 80 Bampton J 29 benefit of the doubt and reported that she was unable to reason about the wrongfulness of her conduct. 111 Dr Nambiar described Ms Rigney’s presentation in the first police interview as quite sedated and vague, noting that she did not seem to be answering any questions. In the second police interview, he described her as quite reactive, verbose, and less cooperative. When he viewed the second police interview, Dr Nambiar said it became a lot clearer that Ms Rigney was able to provide more information about what had occurred, including detailing a whole range of different scenarios and completely removing herself from the stabbing. This suggested to him that there was a degree of either evasiveness on Ms Rigney’s part, or that she was trying to mislead. Together with the information he already had, this altered his opinion that Ms Rigney’s mental impairment was linked to the stabbing, considering that there may have been another motive. Therefore, he could not say, on balance, that the stabbing was related to Ms Rigney’s mental impairment. 112 Dr Nambiar was asked to explain the reference in his second report to there being no evidence of formal thought disorder in the second police interview. Dr Nambiar explained that thought disorder affects how a person organises their thoughts and can be in terms of form or content. He explained disorders in terms of form affect how a person organises their thoughts, which might result in them jumping between topics in conversation without any connection. These are called loose associations. Disorders in terms of content manifest in delusions, or fixed form beliefs. Dr Nambiar said there are degrees of formal thought disorder. 113 Dr Nambiar was shown the video of the second police interview during his evidence and asked to consider whether anything in the video reflected a symptom of schizophrenia. Dr Nambiar said Ms Rigney presented as quite lucid and that she was not exhibiting any symptoms that were overtly related to schizophrenia. When asked about Ms Rigney’s denial of being arrested for murder, he said that this is not necessarily a symptom of schizophrenia. 114 Dr Nambiar explained that specific questions would have to have been asked of Ms Rigney to try and draw out symptoms if they were present but that if she were floridly psychotic, the symptoms would be obvious, such as behaving strangely or not making sense. He said there was not any significance in Ms Rigney smiling during the second police interview and that he did not notice any persistent thought disorder or hallucinations that could have motivated Ms Rigney to commit the stabbing. Dr Nambiar explained that in his experience of assessing accused persons under s 269C, there is usually evidence of a delusional thought linked to the alleged conduct or there are persistent command hallucinations that the person finds overwhelming and unable to resist. 115 Dr Nambiar also considered that there was a difference in how Ms Rigney engaged with him when he interviewed her for his second report, saying that she was obviously more stable after having received further treatment in the absence -- 31 of 114 -- [2025] SASC 80 Bampton J 30 of any illicit drugs. He said she was unwilling to discuss any aspects the alleged offence, in contrast to her attitude during his first interview with her. 116 Dr Nambiar formed the opinion that Ms Rigney was not frank with him during his second interview. 117 Dr Nambiar explained it is important to note that when a person is asked certain questions, if the person freely admits to some things while refusing to talk about others, the clinician queries the motive behind that behaviour. Cross-examination of Dr Nambiar 118 Dr Nambiar was cross-examined about Ms Rigney being overdue for the depot aripiprazole at the time of the stabbing. Dr Nambiar explained that while the injection was one day overdue, administration of antipsychotics is not a perfect science and they are often given two or three days either side of the due date. It was put to Dr Nambiar that the antipsychotic medication Ms Rigney had been taking was not effective. He said it was only partially effective. It was put to him that whilst the antipsychotic medication was at a therapeutic level at the time of the stabbing, it was a therapeutic level of a drug that was not effective. Dr Nambiar again said it was partially effective, agreed that it was not entirely effective at preventing psychoses and explained there is no medication that prevents psychoses entirely. 119 Dr Nambiar agreed in cross-examination that when he prepared his first report, Ms Rigney was not able to describe her thought processes or any symptoms she may have been experiencing at the time of the stabbing. When asked how he had formed a conclusion on Ms Rigney’s competence in the absence of such information, Dr Nambiar said his conclusion was based on the information he had been provided at the time, which demonstrated she had an established illness, that she had symptoms of schizophrenia that appeared to be chronic and resistant to treatment, and that, at the time of her first police interview, she seemed to be sedated. Dr Nambiar said it was difficult to establish what symptoms she was experiencing at the time of the stabbing, but that the first police interview was the source of information most proximate to the stabbing that was available to him. He summarised his opinion as being that “she had symptoms of schizophrenia and more likely than not, because there was no other evidence to challenge that in [his] mind, that it was related to the offence”. 120 Dr Nambiar agreed the nature of the attack was also a relevant consideration. It was put to him that the nature of the attack, namely the 34 stab wounds, was grossly disproportionate to having been rebuffed in relation to an attempt to purchase cannabis. It was put to Dr Nambiar that these circumstances were more consistent with the stabbing being the product of a psychotic motive than a non-psychotic motive. Dr Nambiar said that was not necessarily so, but at the time of his first report with the lack of information he had, he gave Ms Rigney the benefit of the doubt. -- 32 of 114 -- [2025] SASC 80 Bampton J 31 121 Dr Nambiar agreed that collateral information indicated that Ms Rigney had gone to Maria Luis’ house to obtain cannabis and either could not, or believed she could not do so. Dr Nambiar agreed that from the information he had at the time of his first report, there was evidence of conflict or tension between Maria Luis and Ms Rigney in relation to access to drugs. It was pointed out to Dr Nambiar that the possibility of the stabbing being linked to a drug-related conflict did not dissuade him from reaching his opinion, at the time he prepared his first report, that the most likely explanation for the stabbing was a psychotic episode. He replied with, “not with the information I had at the time, no”. 122 Dr Nambiar agreed that he was aware of Ms Rigney’s attendances at Service SA and Cash Converters. He accepted that the inference he drew is that she went and obtained money for the purposes of buying drugs, and that this conduct is not inconsistent with her being psychotic at the time. He was asked whether the conduct was inconsistent with her being floridly psychotic. Dr Nambiar said if Ms Rigney were floridly psychotic, it would be less likely that she would be able to attend to those tasks, but that it would depend on the degree of psychosis. He agreed that it is well established that a person in a psychotic state can engage in apparently purposeful conduct. He agreed that the conclusion in his first report that Ms Rigney was mentally incompetent was not undermined by her attendances at Service SA and Cash Converters. 123 Dr Nambiar also said he was aware at the time of his first report from the information provided to him, including CCTV footage, that Ms Rigney attended Maria Luis’ home on two occasions on 7 December 2018. He agreed Ms Rigney’s conduct captured on the CCTV during the first attendance was not inconsistent with her being psychotic at the time. He said he was not quite sure how to interpret Ms Rigney’s conduct in knocking over the shopping trolley. He suggested that it may be either unexplained or because she was angry. Overall, he agreed that nothing in the CCTV caused him to doubt the correctness of the view he expressed in his first report that she was mentally incompetent. 124 With respect to Ms Rigney’s second visit to the Luis house, Dr Nambiar agreed that the conduct depicted on the CCTV footage was not inconsistent with Ms Rigney being psychotic at the time. He agreed that based on the information he had to hand at the time of preparing his first report, he concluded that she was so psychotic when she arrived at Maria Luis’ house that she could not reason that her behaviour in stabbing Maria Luis was wrong. He agreed that for Ms Rigney to have been unable to reason about whether her conduct was wrong, she would have to have been floridly psychotic. Dr Nambiar agreed Ms Rigney’s behaviour as depicted in the CCTV footage of the second visit was, in his view at the time of his first report, not inconsistent with her being floridly psychotic. Further, he said he made an assumption, at the time of writing his first report, that she would have still been floridly psychotic at the time she was depicted walking along Goodman Avenue in the direction of her home without collecting her backpack. He repeated that he made this assumption on the information he had at the time. -- 33 of 114 -- [2025] SASC 80 Bampton J 32 125 Dr Nambiar agreed that, at the time of writing of his first report, he had the video of the first police interview that commenced after 11:00 pm on 7 December 2018. He accepted that while he did not have the video of the second police interview, the account given by Ms Rigney during that interview was summarised in the facts of charge and the prosecution case statement, both of which he had. The summary in the prosecution case statement states: The accused [was] interviewed on the afternoon of 8 December [2018]. During the interview the accused gave varying versions explaining her presence at the deceased’s premises at the time of the alleged offending. She told police that there was another male, potentially two or more, who stabbed the deceased in her presence and that she then left the premises. It is alleged that the statements made by the accused during her interview are deliberate lies. On the Crown case those lies are relied upon as implied admissions of guilt. 126 Dr Nambiar agreed that at the time he wrote his first report, he was aware Ms Rigney had given an account inconsistent with the prosecution’s contention that she was the culprit, including varying explanations for her presence at Maria Luis’ home. He agreed that, at that time, none of that information caused him to retreat from the view expressed in his first report that Ms Rigney was psychotic at the time of the stabbing and that she was mentally incompetent to commit the offence. However, he stated that it was not until Ms Rigney’s alleged lies and explanations in the second police interview were provided in video format that he was able to see them in context, which caused him to change his mind. 127 Defence counsel then took Dr Nambiar to the nature of Ms Rigney’s account and memory at the time of his first report, which is set out at points 6 to 7 in [88] above. Dr Nambiar agreed that when he wrote the first report, he did not believe that Ms Rigney’s inability to recall or explain various events, including her attendance at Maria Luis’ home, was inconsistent with his conclusion that she was mentally incompetent. He explained that he considered that she may not remember those matters. Dr Nambiar agreed a person who suffers from a psychosis because of schizophrenia may experience total or partial amnesia. He agreed that people can have difficulties in remembering events after experiencing extreme excitement in a psychotic state due to schizophrenia and/or other psychiatric conditions. 128 However, while Dr Nambiar agreed that at the time of his first report, he considered that there may have been legitimate explanations for Ms Rigney’s inability to recall certain events, when directed to the statement in his first report that, “[h]er inability to recall all the details appears to be evasive, perhaps in order to naturally deny allegations”, Dr Nambiar explained that he also considered the possibility that Ms Rigney did not want to tell the truth. Dr Nambiar said this did not detract from his initial view that she was mentally incompetent. 129 Dr Nambiar was asked whether he would dispute the opinion of Prof Coyle and Prof Morris that, in addition to a schizophrenic psychosis, the fact that Ms Rigney had been sexually abused as a child could have contributed to her amnesia. Dr Nambiar said it would depend on the context. He explained that “in terms of sexual abuse we’re talking about a specific event and so to trigger anxiety -- 34 of 114 -- [2025] SASC 80 Bampton J 33 there would have to be certain conditions that would provide that anxiety, that level of anxiety”. It was put to him that if someone had experience of sexual abuse and was then subjected to circumstances such as the stabbing, in which they engaged in hyperarousal conduct such as Ms Rigney did on 7 December 2018, that child sexual abuse could contribute to the effects of amnesia or the possibility of amnesia. Dr Nambiar said it could, but not necessarily. 130 It was put to Dr Nambiar that post-traumatic stress disorder (“PTSD”) can have the same effect when superimposed on schizophrenia. Dr Nambiar said, again, it would depend on the context, noting that PTSD is not something a person experiences all the time but rather, there are certain triggers that activate the person’s symptoms. When questioned about the evidence suggesting Ms Rigney had complex PTSD, Dr Nambiar explained that complex PTSD is different to PTSD per se. He said the former is simply another way of formulating BPD, whereas the latter comprises an acute, chronic reaction to a specific, quite traumatic event. 131 It was put to Dr Nambiar that a triggering event could occur in the context of sexual abuse such that difficulty with memory is embedded from that time on. Dr Nambiar said it would depend on the trigger. It was suggested to him the trigger could be a general hyperarousal situation, which he rejected, explaining that a trigger would cause a hyperarousal situation that could then possibly inflame symptoms. It was put to him that the hyperarousal experienced by Ms Rigney during the incident at the Luis front door could be a trigger for PTSD. Dr Nambiar said “[p]ossibly. We can’t really say because we don’t really know”. 132 Dr Nambiar said he disputed the diagnosis of PTSD because, in his view, Ms Rigney has more of a complex PTSD. 133 Overall, Dr Nambiar said that at the time of his first report, it was hard to say whether Ms Rigney’s inability to recall events on the day of the stabbing was a consequence of psychosis or whether Ms Rigney had feigned memory loss, noting that he agreed that it could be a combination of those factors. He agreed, notwithstanding that her account may have been a lie, she could have been floridly psychotic at the time. 134 Dr Nambiar was then taken to his second report, where he states: On that basis, I would like to alter my opinion to the proposition that it is my view that more likely than not, that although Ms Rigney’s mental processes were impaired at the material time of the offence, that the evidence provided in relation to her conduct before and immediately after the offence, including the police interview on 8/12/18 that I did not have the opportunity to view for my first report, would suggest that a mental impairment defence is not available to her. Dr Nambiar agreed that the conduct before the stabbing he referred to in the foregoing excerpt included Ms Rigney attending Maria Luis’ address, on her account, to purchase drugs, having obtained money from Cash Converters, and -- 35 of 114 -- [2025] SASC 80 Bampton J 34 Ms Rigney removing and concealing a bulky backpack a short distance from Maria Luis’ address. He agreed he was aware of this conduct at the time of his first report. 135 Dr Nambiar was referred to the statement in the second proposition in the DPP letter that this conduct “demonstrates a degree of composure and order of thought in the immediate lead up to the offence”. He accepted that a person could be psychotic and nonetheless behave in that way, as psychosis does not always dictate abnormal behaviour. In this way, Dr Nambiar compared psychosis to a headache, which would not necessarily influence a person’s conduct but might do so if the headache were severe. Dr Nambiar agreed that when he formulated his first report, he took the view that, notwithstanding the conduct before the stabbing, Ms Rigney would have been floridly psychotic when the stabbing occurred. However, Dr Nambiar reiterated that he had not received the video of the second police interview at the time he prepared his first report. 136 Dr Nambiar was asked about the fourth proposition in the DPP letter, which is as follows: There is evidence of some motive: she had attended at the deceased’s address on 2nd or 3rd of December (Statement of Kirsty Francis 16.1.19) and remonstrated with her in the process of looking for drugs. She attended there on the day of the murder, twice. On the second occasion, the deceased was stabbed. She told the police that the deceased presented some resistance to selling her drugs when she first started going there (Record of Interview – Page 12). An inference arises that she was not supplied drugs as she had requested. Dr Nambiar agreed he had the information contained in the fourth proposition when he formulated his first report. He agreed that he had inferred from this collateral information that Maria Luis had resisted selling drugs to Ms Rigney. 137 Dr Nambiar was then asked about the fifth proposition in the DPP letter, which provides: The evidence of the number of stab wounds gives rise to an inference of an emotional excitement. This is consistent with poor frustration control in the face of conflict as a matter of personality as distinct from an operating psychosis. Dr Nambiar agreed he also had the information contained in this proposition at the time he expressed his first opinion. He agreed that while what appears to be a disproportionately violent response might be consistent with poor frustration control, at the time of his first report, he was satisfied that, on balance, it was more consistent with a psychotic reaction. 138 Dr Nambiar said that the main reason he changed his opinion was because the video of the second police interview gave him a better insight into Ms Rigney’s mental state close to the time of the stabbing. He said that when this was considered together with the entirety of the information he had, it caused him to change his mind because he was considering whether there was a motive. Dr Nambiar again said he gave Ms Rigney the benefit of the doubt in his first -- 36 of 114 -- [2025] SASC 80 Bampton J 35 report in the absence of the information he gleaned regarding her mental state during the second police interview. 139 It was put to Dr Nambiar that it was Ms Rigney’s appearance and behaviour in the second police interview that caused him to change his mind rather than its content. Dr Nambiar answered: No, it was actually the fact that there was an absence of thought disorder and the content as well, in that there were no delusions and she didn’t appear to be responding to any auditory hallucinations. Dr Nambiar explained that he performed a mental state examination of Ms Rigney based on her presentation in the video of the second police interview just as he would have done if he were interviewing her himself. Dr Nambiar was asked whether it was his view that she was not psychotic at the time of the interview. Dr Nambiar clarified that he did not say that she was not psychotic at the time of the second police interview but rather, she was not exhibiting any thought disorder or hallucinations that would tie her behaviour to the offence. He was asked about the statement in his second report, wherein he concludes: Having viewed the record of interview conducted on 8/12/18 at between the hours of two and three AM, her appearance, conduct and in particular her conversation, was not consistent with psychosis. It was suggested to Dr Nambiar that this conclusion does not allow for the possibility of any form of psychosis. Dr Nambiar agreed but said that if “[he had] interviewed her [himself, he] would then have probed her more to see if [he] could draw out symptoms”. Dr Nambiar explained that as Ms Rigney had schizophrenia, she would always have some symptoms, but that they were not frank enough to be observed during the second police interview. 140 When asked whether he disagreed with the views expressed by other expert witnesses that Ms Rigney was saying and doing things in the second police interview that were indicative of psychosis, Dr Nambiar reiterated that he could not see any evidence of psychosis. 141 Dr Nambiar agreed with defence counsel’s summation of his opinion as follows: … in relation to the interview on 8 December … because Ms Rigney appeared more lucid and composed and responsive to questions that she is less likely to have been acutely psychotic at the time of the stabbing incident. 142 While Dr Nambiar agreed that the level or intensity of psychosis may wax and wane over time, he said it was unlikely that Ms Rigney could have been floridly or severely psychotic at the time of the stabbing, with her psychosis receding in the short period of time between then and the second police interview, unless “she had been treated with medication in that time”. Dr Nambiar was asked whether there is scientific data concerning the standard rate of dissipation of -- 37 of 114 -- [2025] SASC 80 Bampton J 36 psychotic symptoms. Dr Nambiar said that there is no such data but that thought disorder of form, in his experience of patients with chronic, treatment-resistant schizophrenia, remains constant and can take weeks or months, rarely days to recede. When it was pointed out to Dr Nambiar that the second police interview took place between 2:00 pm and 3:00 pm on 8 December 2018 rather than 2:00 am and 3:00 am as he had mistakenly thought, he said that this made no difference to his opinion, “given the type of psychosis, it’s chronic, if she was that disordered it wouldn’t have improved in that short space of time”. 143 Dr Nambiar was referred to the opinion in his second report that: It is complicated to determine the rate [at] which it is expected that [drug-induced] symptoms of schizophrenia would dissipate in the context of an already established diagnosis of schizophrenia. The physical, emotional and cognitive effects of acute intoxication can wear off fairly quickly (in a matter of days) and yet the psychotic symptoms of schizophrenia that had been precipitated by that intoxication can still remain for many weeks or months. Dr Nambiar agreed that drug-induced psychosis can last a matter of hours in the absence of schizophrenia, explaining that the duration of psychosis is usually one of the tests employed to identify a drug-induced psychotic episode as distinct from schizophrenia. 144 Dr Nambiar said he knows all the forensic psychiatrists practising in Australia because he is on a committee with them. He said that Prof Morris is not someone he is familiar with in this context. Dr Ferris 145 Dr Ferris obtained her specialist qualifications in 2009 and completed the Advanced Training Certificate in Forensic Psychiatry in 2014. Dr Ferris is employed as a Forensic Consultant Psychiatrist by the South Australian Forensic Mental Health Service with the Forensic Community Mental Health Team. She consults with people on forensic licences in the community, coordinates the statewide forensic consultation liaison service to mental health inpatient units, and provides consultant supervision including in psychiatric clinics at the Adelaide Women’s Prison (“AWP”). 146 Dr Ferris gave evidence she has provided opinions and evidence to the Court regarding fitness and competence regularly since 2007. Dr Ferris’ reports dated 21 August and 20 September 2020 147 Dr Ferris prepared a report pursuant to s 269WA dated 21 August 2020 following her interview with Ms Rigney on 25 June 2020, having first assessed her soon after her admission to the AWP. At the time of writing the report, Dr Ferris reported that she had had contact with Ms Rigney at the AWP on five or six occasions in her capacity as a visiting forensic psychiatrist. Dr Ferris reported that Ms Rigney was, at the time of writing her report in August 2020, mentally unfit to stand trial. -- 38 of 114 -- [2025] SASC 80 Bampton J 37 148 Dr Ferris stated that, in her opinion, Ms Rigney had a mental impairment at the time of the stabbing; namely, chronic paranoid schizophrenia. Dr Ferris further reported that: Certainly, Ms Rigney failed to provide any history and any acceptance or explanation for her movements between leaving [Service SA] and being arrested by the police. She claims to not remember and not know her movements during this time. It is possible that she is feigning this memory loss. It is also a possibility that due to her disturbed mental state and disorganised thought processes at the time of the offence, coupled with proven marijuana use and low levels of amphetamine use, that she has had disturbances in her memory. (Emphasis added) 149 Dr Ferris concluded her report stating Ms Rigney would have known the nature and quality of her conduct but that she was most likely, by reason of her paranoid schizophrenia, unable to reason about whether her conduct was wrong as perceived by reasonable people. She referred to collateral information and the two police interviews, as well as her interviews of Ms Rigney, saying that there is evidence of psychotic symptoms, including delusions, hallucinations, thought disorders and incongruent mental state. Dr Ferris said she was unable to comment on whether Ms Rigney was able to control her conduct. Accordingly, Dr Ferris considered that Ms Rigney was mentally incompetent at the time of the stabbing. 150 In her addendum report dated 20 September 2020, which was provided pursuant to a further s 269WA order, Dr Ferris confirmed Ms Rigney suffered treatment-resistant paranoid schizophrenia with ongoing psychotic symptoms despite being administered depot antipsychotic medication. Dr Ferris stated she had concerns that Ms Rigney’s inability to discuss her mental state, thought processes, motive, or any psychotic symptoms at the time of the stabbing may be related directly to her ongoing psychosis. She said: It is difficult to be definitive in such a case, where there is limited witness accounts and self-report and I recognise the limitations to my considerations. However, I believe that … her global functioning was so affected that her reasoning, judgement and thinking would have had to [have been] affected. She presented with perceptual disturbances and guarded, perplexed and incongruent mental state and likely would have had disturbed thought processes secondary to voiced auditory hallucinations. (Emphasis added) 151 Dr Ferris concluded this report stating that it remained her opinion that, on the balance of probabilities, Ms Rigney would not have been able to reason about whether her conduct was wrong, as perceived by reasonable people. Dr Ferris’ report dated 23 March 2021 152 Dr Ferris considered Ms Rigney was fit to stand trial and that the s 269C defence was available to her in a report dated 23 March 2021. Dr Ferris reported that she was confident, after her repeated assessments of Ms Rigney, that her psychotic symptoms are secondary to her schizophrenia, which were ongoing -- 39 of 114 -- [2025] SASC 80 Bampton J 38 despite over two years’ of mental health treatment with numerous antipsychotic medications and abstinence from illicit drugs. Dr Ferris stated it was her opinion that Ms Rigney was presenting with an unusual affect during the second police interview, including inappropriately giggling and smiling, and that she was responding to auditory hallucinations. She noted that at other times in the second police interview, Ms Rigney appeared lucid and appropriate. Dr Ferris stated she was unable to comment on the content of the auditory hallucinations or whether they bore any direct relationship to the stabbing. However, she said that knowing Ms Rigney well over two years, it was her suspicion that her thought processes were disturbed at the time. 153 Dr Ferris said that the state of Ms Rigney’s accommodation on Goodman Avenue was relevant collateral information in assessing her mental state. She stated the disorganisation of Ms Rigney’s bedroom, complete with random extensive disorganised words, drawings, and diagrams over three of the walls and over the blinds, is suggestive of a person presenting with disturbed and distorted thought processes. Dr Ferris acknowledged that she could not be sure that these drawings were done by Ms Rigney, but that they represented a chaotic, disorganised environment and significantly poor self-care. 154 Dr Ferris stated that, in her opinion, Ms Rigney continued to present with treatment-resistant schizophrenia, which opinion she said was supported by collateral history provided by Ms Rigney’s treating team at JNH, nursing staff observations, and Ms Rigney’s self-report. Dr Ferris said it continued to be her opinion that for many years prior to the stabbing, Ms Rigney had schizophrenia that was misdiagnosed as a drug-induced psychosis. Dr Ferris stated it was her opinion that in the months leading up to the stabbing, Ms Rigney was continuing to present with acute psychotic symptoms, which she believed Ms Rigney continued to suffer after the stabbing. Dr Ferris noted Ms Rigney remained unable to provide a self-report regarding her mental state at the time of the stabbing and that she may well be being deliberately evasive. Dr Ferris stated that it could also be that her global functioning was so affected by her psychosis and comorbid illicit substance use that her ability to remember this period and her mental state at the time. 155 Dr Ferris stated that she recognised the limitations of her conclusions, but that it continued to be her opinion that Ms Rigney was presenting with a disturbed mental state and that her global functioning was so affected that her reasoning, judgement, and thought processes (influenced by auditory hallucinations) were impaired. She stated she believed that Ms Rigney would have known the nature and quality of her conduct and, although she may have had an intermittent inability to control her conduct, it was her opinion that Ms Rigney was most likely able to control her conduct. However, she said that on the balance of probabilities, Ms Rigney’s impairment would have led her to be unable to reason about whether her conduct was wrong as perceived by reasonable people at the time of the stabbing. Accordingly, Dr Ferris considered Ms Rigney was mentally incompetent to commit the offence of murder. -- 40 of 114 -- [2025] SASC 80 Bampton J 39 Dr Ferris’ report dated 30 April 2021 156 In her report dated 30 April 2021, Dr Ferris stated, based on an assessment on 22 April 2021, that Ms Rigney would have difficulties understanding the nature of court proceedings, and following the evidence and the course of the proceedings, such that Dr Ferris considered she was unfit to plead and stand trial. Dr Ferris stated she was hopeful that over the next three to six months, Ms Rigney could be stabilised on triple therapy antipsychotic medication and that there may consequently be an improvement in her symptomology and her thought processes that would render her fit to stand trial. 157 As discussed earlier, it was on the basis of this report and Dr Nambiar’s report dated 28 April 2021 that the investigation into Ms Rigney’s mental competence to commit the alleged offending listed for hearing on 6 May 2021 was vacated. Dr Ferris’ report dated 26 July 2021 158 In her report dated 26 July 2021, Dr Ferris noted that there was a significant improvement in Ms Rigney’s oversedation when compared to her last interview in April 2021, and that her attention, distractibility, and concentration was also much improved. Dr Ferris noted that, compared to previous interviews, Ms Rigney was not irritable or dismissive and did not make rude comments. Further, on no occasion during the interview did Ms Rigney appear to be responding to internal stimuli. Accordingly, Dr Ferris recorded that Ms Rigney’s mental state had improved since her last review and that there was no evidence of formal thought disorder of speech form or poverty of speech, but that Ms Rigney identified ongoing intermittent perceptual disturbances (mainly auditory hallucinations at night) and delusional beliefs. Dr Ferris reported that Ms Rigney’s insight and judgement appeared to have slightly improved. 159 Dr Ferris recorded that when she questioned Ms Rigney about the prosecution evidence, Ms Rigney denied remembering attending the Luis house in the late afternoon on the day of the stabbing, being in the house, talking to Maria Luis, or possessing a knife. She was unable to remember any specific thought content, stating, “I don’t remember” in response to many questions asked by Dr Ferris and on one occasion stating, “I wouldn’t do that”. Ms Rigney reiterated that the last thing she remembered was “getting money at Cashies”, then “police barging in and pointing guns [at her]”. 160 Dr Ferris determined that Ms Rigney’s mental processes were not so impaired that she was unfit to stand trial. Accordingly, Dr Ferris concluded that Ms Rigney was fit to plead and stand trial. 161 Dr Ferris stated that being given the opportunity to review Ms Rigney with an improved mental state and engagement in the interview process had allowed her to reconsider the question of mental incompetence. Dr Ferris reported that she remained strongly of the view that Ms Rigney suffered from a mental impairment, namely treatment-resistant schizophrenia. She stated it continued to be her opinion -- 41 of 114 -- [2025] SASC 80 Bampton J 40 that she was suffering from this condition from around the age of 17 years, though it appeared it was difficult to extensively assess her in the community due to her guarded presentation, irritability, lack of engagement and compliance with mental health assessments, and refusal to disclose symptomology. Dr Ferris also noted that assessment of Ms Rigney was complicated by comorbidities of illicit substance use, borderline personality dysfunction, and significant developmental trauma. Dr Ferris stated that it remained her opinion that Ms Rigney’s ongoing illicit substance use exacerbated, rather than substantially contributed to, the underlying psychotic symptoms of her schizophrenia. Dr Ferris commented that this conclusion was supported by clinical observation of residual psychotic symptoms over the previous years, including auditory hallucinations, delusional beliefs, and disturbed thought processes, despite abstinence from illicit substances and compliance with triple therapy antipsychotic medications. 162 Dr Ferris continued to be of the opinion that Ms Rigney was presenting with acute psychotic symptoms in the months leading up to the stabbing. She also maintained the view that Ms Rigney was experiencing episodes of perceptual disturbances in the second police interview, though the content and any relevance of those hallucinatory experiences to the stabbing remained unknown. 163 Noting Ms Rigney’s improved presentation, Dr Ferris stated that she believed that Ms Rigney had the ability to provide further truthful information about her thought processes, behaviour, and possible psychotic symptoms around the time of the stabbing. Dr Ferris pointed out that she had previously noted that Ms Rigney’s inability to provide such a self-report may have been a product of evasiveness. Dr Ferris stated that following her assessment on 22 July 2021, she was more certain that this was the case. 164 Dr Ferris concluded her report by stating that she remained of the opinion that Ms Rigney was likely to have been experiencing psychotic symptoms secondary to her chronic schizophrenia at the time of the stabbing. However, she was now unable to state that on the balance of probabilities, Ms Rigney’s mental impairment was influencing and impairing her thought processes and actions at the material time such that she was unable to reason about whether her conduct was wrong as perceived by reasonable people. Accordingly, Dr Ferris stated that she no longer believed Ms Rigney had the s 269C defence available to her. Dr Ferris’ evidence 165 Dr Ferris explained in evidence that she first had contact with Ms Rigney in January 2019. Ms Rigney had previously been seen by one of her colleagues, Dr Cassie Smith in December 2018. 166 At the initial consultation on 3 January 2019, Dr Ferris was informed by Ms Rigney that she felt that she had a split personality disorder with 12 personalities. She noted that Ms Rigney was very guarded, in that she was not forthcoming with information and refused to elaborate on answers at times. Dr Ferris noted that she had been prescribed depot aripiprazole, and following -- 42 of 114 -- [2025] SASC 80 Bampton J 41 Dr Smith’s assessment, was also prescribed oral olanzapine, as it was suspected that Ms Rigney was presenting with psychotic symptoms.4 167 Dr Ferris noted that Ms Rigney giggled throughout the interview, was fatuous in affect, and at times displayed intense eye contact. It was Dr Ferris’ clinical opinion that Ms Rigney was actively responding to perceptual disturbances; namely, auditory hallucinations. Dr Ferris considered that she was presenting with a psychosis, which, in her opinion, was against a background of what was documented as BPD, chronic PTSD, and a history of illicit substance use, based on the limited background information she had at the time. 168 By reference to the DSM,5 Dr Ferris explained that BPD is pervasive and lifelong, characterised by patterns of unstable and intense interpersonal relationships and alternating between extremes of idealisation and devaluation. Impulsivity, mood swings, and difficulty controlling anger are features of the disorder as well as self-damaging activities like substance abuse. 169 Dr Ferris was asked to identify the basis on which she concluded that Ms Rigney was responding to auditory hallucinations. Dr Ferris explained that, in her clinical experience, a person responding to auditory hallucinations may often stare off into the distance and sometimes, their eyes can be seen to flicker as if they are distracted by what is going on in their head. She said that Ms Rigney did this on numerous occasions. Dr Ferris documented her suspicion that, during the interview, Ms Rigney was presenting not only with psychosis, but possibly a more chronic, evolving psychotic illness. 170 Dr Ferris estimated that she saw Ms Rigney at least 10 times up until October 2019, during which time, having regard to symptomology, she diagnosed her with paranoid schizophrenia, which she suspected might be a treatment-resistant schizophrenia. Dr Ferris explained that she revised Ms Rigney’s diagnosis of BPD recorded in prior admissions to borderline personality traits, as she did not consider Ms Rigney’s symptoms reached the threshold for the disorder. She noted that Ms Rigney reported ongoing psychotic symptoms of varying intensity and presented with both delusions and auditory hallucinations. Dr Ferris said that once Ms Rigney’s medication had been altered as described earlier, she became a little less irritable. Around this time, Dr Ferris also placed her on the waiting list for JNH, as she considered admission to JNH would assist in the understanding and treatment of her psychiatric symptoms. 171 In May 2019, Ms Rigney continued to present with psychotic symptoms, including paranoia about what Dr Ferris was writing down during her interview. She was also guarded, stating “[t]hat’s none of your business” when questioned about court and how she was going in the AWP. Dr Ferris reported that Ms Rigney 4 The antipsychotic regime was altered in February 2019, whereby depot zuclopenthixol was prescribed in lieu of aripiprazole. In May 2019, olanzapine was ceased while Ms Rigney remained on depot zuclopenthixol. 5 Diagnostic and Statistical Manual of Mental Disorders. -- 43 of 114 -- [2025] SASC 80 Bampton J 42 remained guarded and paranoid during an interview in August 2019, and that she denied having paranoid or persecutory thoughts and auditory hallucinations, despite appearing to respond to perceptual disturbances during the interview. She also continued to present with delusions, along with suspected auditory hallucinations, during an interview in September 2019. 172 On 22 October 2019, Ms Rigney was transferred to JNH where she was commenced on clozapine, while also remaining on zuclopenthixol because her psychiatric illness was so severe. Ms Rigney was transferred back to the AWP on 31 December 2019, having reached a therapeutic dose of clozapine, although she was noted to still be experiencing some ongoing mild psychotic symptoms. 173 Dr Ferris gave evidence that in interviewing Ms Rigney for her report dated 21 August 2020, Ms Rigney was intermittently irritable when asked questions that she did not want to answer, and at times was distracted. She was reluctant to answer questions regarding her mental state, often answering “I don’t know” or “I’m fine”. Ms Rigney denied any ongoing paranoia or bizarre somatic complaints and was dismissive of any questions relating to this issue. Dr Ferris noted that she had ongoing elements of a guarded mental state, which Dr Ferris said manifests in the person not being forthcoming with answers. This is often seen in people with underlying psychoses, particularly if they have been masking the symptoms. Dr Ferris said guarded mental state can also be seen in personality dysfunction. 174 Dr Ferris was asked how a person masks the symptoms of schizophrenia. Dr Ferris said it occurs when a person denies or avoids answering questions about symptoms, the existence of which can be identified by reference to the examiner’s experience or collateral information. She said it can be deliberate or the result of the paranoid component of the psychotic illness. In relation to personality traits that might manifest in guardedness, Dr Ferris explained that usually this would appear as more wilful in terms of deliberately not answering a question and being avoidant. Its identification requires nuanced consideration of the patient’s whole mental state thorough clinical assessment, the patient’s words, collateral information, and the presence or absence of psychotic symptoms. She repeated that it would come down to clinical judgement to differentiate between the two forms of guardedness. 175 Dr Ferris was asked whether she had, at the time of writing her report dated 21 August 2020, any uncertainty about whether Ms Rigney’s guardedness was referrable to matters of personality or schizophrenia. Dr Ferris pointed to the statement in her report that, “[i]t is possible [Ms Rigney] is feigning [her] memory loss”. She went on to identify the alternative possibility that due to her disturbed mental state and disorganised thought processes at the time of the stabbing, coupled with drug use, she had disturbances in her memory. 176 Dr Ferris remained of the view that the s 269C defence was available to Ms Rigney until her assessment on 22 July 2021. She noted in her report dated 26 July 2021 that Ms Rigney had a much-improved mental state, although she -- 44 of 114 -- [2025] SASC 80 Bampton J 43 reported having ongoing intermittent perceptual disturbances, which were mainly auditory hallucinations at night and delusional beliefs. Dr Ferris said that Ms Rigney had insight into the fact that these were hallucinations. Dr Ferris said that the extent of Ms Rigney’s insight into her condition fluctuated owing to the fluctuating nature of her treatment-resistant schizophrenia, and that her insight might be more impaired in periods of stress, with illicit substance use, or when her psychosis is decompensating. However, Dr Ferris did not believe that her insight was ever impaired to the extent that she was going to act on any of her hallucinations in a way that posed a risk to herself or others. 177 Dr Ferris said Ms Rigney presented with an improved mental state, ability to respond to questions, and engagement in the interview on 22 July 2021, with no overt evidence of psychoses. Dr Ferris said this was the first time since she had first interviewed Ms Rigney that psychotic symptoms were absent during the assessment. She formed the view that Ms Rigney was able to provide further information about her thought processes, behaviour, and any psychotic symptoms at the time of the stabbing. Dr Ferris said she was more certain after this assessment that Ms Rigney was deliberately withholding information. 178 I asked Dr Ferris how I was to make sense of her altered opinion, noting that both she and Dr Nambiar were of the opinion that the s 296C defence was available to Ms Rigney when they assessed her closer to the stabbing. I pointed out that Dr Ferris changed her opinion almost two years later, after Ms Rigney had been receiving treatment. Dr Ferris said: Yes, I understand what you’re asking. I believe it is further clinical assessment. It is further information within the interview and the way that she answered the questions that I put to her. As I’ve said in all of my reports, there were elements of her being evasive in regards to answering in the time line, there were inconsistencies in regards to her remembering some events and not remembering events and on this last interview I felt that with an improved mental state I was more able to ask specifics of those questions and I guess, in a way, try to ask questions to catch her out to see whether I felt she was giving truthful answers in regard to her ability to remember that period of time and there were inconsistencies between what she had told me, what she had remembered with [the other doctors] and failed to remember with me … 179 Dr Ferris said, based on her clinical judgement, she formed the opinion that Ms Rigney had a wilful lack of recollection about some matters surrounding the stabbing, which Dr Ferris suspected was due to fear of the consequences of her actions rather than being secondary to psychotic symptoms. I asked how Dr Ferris could distinguish a wilful lack of recollection from a loss of memory that is a product of her thought disorder and psychotic illness. Dr Ferris reiterated her opinion that Ms Rigney was not presenting with a thought disorder or psychotic symptoms at the time that she was last interviewed. She said Ms Rigney’s presentation had improved such that Dr Ferris was able to ask many of the questions that had been irritably shut down by Ms Rigney in previous interviews. This allowed her to resolve the doubts she had expressed in her earlier reports. -- 45 of 114 -- [2025] SASC 80 Bampton J 44 180 When asked what a psychiatrist would be trying to ascertain regarding a person’s thought processes at the time of alleged offending, Dr Ferris suggested a command hallucination, a delusional belief such as a persecutory or paranoid belief, or a visual hallucination involving the person believing that the victim is the devil could be involved. She said these psychotic symptoms all affect someone’s thought processes, such that the person might act as a consequence of that thought. Noting that Ms Rigney stated she had no memory of the stabbing, Dr Ferris explained she had not been able to link the stabbing with the content of any psychotic symptoms. Dr Ferris further said that none of the information regarding the lead up to the stabbing and the period of time afterwards led her to believe that Ms Rigney’s behaviour was driven by a psychotic belief. 181 Dr Ferris said that forensic psychiatrists very regularly see offenders who have acute psychotic symptoms but do not satisfy the s 269C criteria because a link between their thought processes and the offending cannot be identified. She said: So it’s actually not that uncommon for people with treatment-resistant schizophrenia who are psychotic to not automatically get a [s 269C] defence. There needs to be a knowledge of the content of the psychotic thought that leads to that behaviour. 182 When asked whether she considered there was any significance in the number of stab wounds inflicted by Ms Rigney, Dr Ferris stated that the number of stab wounds does not necessarily indicate that the stabbing occurred secondary to personality on the one hand, or during a period of psychosis on the other. 183 Dr Ferris pointed out that Prof Morris had asserted that she had changed her opinion after receiving the DPP letter, which she said was not the case, noting that she was provided with the DPP letter between her first and second reports. 184 Dr Ferris noted that Prof Morris reasoned that because Ms Rigney was psychotic, the s 269C defence was available to her. Dr Ferris explained that the issue of whether the s 269C defence is available is much more nuanced than that, and that psychotic people are capable of committing offences while knowing the wrongfulness of their actions such that the s 269C defence is not available to them. 185 I asked Dr Ferris about Prof Coyle’s opinion that a history of child sexual abuse and PTSD have to be taken into account when assessing the question of Ms Rigney’s lack of memory. Dr Ferris pointed out that she has alluded to Ms Rigney’s developmental trauma in all her reports, and that Ms Rigney was not forthcoming in relation to those issues. She said there is no denying that Ms Rigney may present with some elements of PTSD but maintained that her primary diagnosis is treatment-resistant paranoid schizophrenia, and certain symptomology that Prof Coyle attributes to PTSD could also be consistent with psychosis. -- 46 of 114 -- [2025] SASC 80 Bampton J 45 Cross-examination of Dr Ferris 186 Dr Ferris confirmed in cross-examination that she was regularly attending on Ms Rigney in the AWP from the beginning of 2019 until her transfer to JNH. 187 Dr Ferris was asked whether the medication Ms Rigney was prescribed for the two years prior to the stabbing was largely ineffective. She said she believed the medication might have made some difference to her symptoms, but that certainly she had residual symptoms throughout that time. 188 It was put to Dr Ferris that Ms Rigney’s presentation during the first police interview was consistent with psychosis. Dr Ferris referred to her report dated 23 March 2021, where she stated: Ms Rigney is noted to present as extremely sedated, has difficulty understanding the processes and on one occasion alluded to her chronic delusion that she was currently pregnant. … she appears to be under the influence of substances of some kind and given her level of sedation, this may well be secondary to her having benzodiazepines in her system or large amounts of marijuana. She clearly was not understanding the processes, questioning whether she’d breached her bail conditions, repeatedly not answering questions and was noted to be staring off into the distance at times in the car ride. She was unable to state why she was in police custody despite being asked numerous times and on one occasion stated “someone died in the morning?” which appeared incongruent. 189 Dr Ferris said that because Ms Rigney had her head at an angle in the video of the first police interview, she could not comment on whether Ms Rigney staring into the distance suggested psychosis. She noted that Ms Rigney made one reference to her longstanding delusion of being pregnant. However, she explained a chronic delusion may be underlying without affecting someone’s behaviour. 190 Dr Ferris agreed that during the second police interview, Ms Rigney appeared to be more responsive and alert. Dr Ferris said despite this, as she was able to see distraction in Ms Rigney’s eyes, she may have been responding to perceptual disturbances at times when she could not answer questions. Dr Ferris reiterated her opinion that on balance, Ms Rigney was likely to have been psychotic at the time of the second police interview. 191 Dr Ferris agreed that the observations made by Dr Smith after examining Ms Rigney on 12 December 2018 were consistent with Ms Rigney being psychotic as at that date. She also agreed that she herself confirmed psychosis when she saw Ms Rigney for the first time on 3 January 2019. Dr Ferris was asked whether, given the history of psychosis, it was highly likely that Ms Rigney would have been psychotic on the day of the stabbing. Dr Ferris said while there is evidence of psychosis leading up to and following the stabbing, she was unable to comment on Ms Rigney’s demeanour and behaviour on the day of the stabbing because Ms Rigney had not been able to provide details to her. It was put to Dr Ferris that in her first three reports, she concluded that Ms Rigney must have been psychotic on the day of the stabbing. Dr Ferris agreed that, based on the information she had from Ms Rigney, along with collateral information, her opinion was that on the -- 47 of 114 -- [2025] SASC 80 Bampton J 46 balance of probabilities, Ms Rigney was unable to reason about whether her conduct was wrong as perceived by reasonable people, and that this was a consequence of her chronic paranoid schizophrenia. Dr Ferris went on to say that in her earlier reports, she recorded the qualifications to, or limitations of, her opinion and noted that she could not prove the veracity of Ms Rigney’s statements regarding her lack of memory. 192 Dr Ferris agreed that if the trial had proceeded in May 2021, she would have given evidence that Ms Rigney was mentally incompetent to commit the alleged murder, while noting her reservations regarding Ms Rigney’s claimed lack of memory. 193 Dr Ferris was cross-examined about the circumstances that caused her to change her opinion on the issue of mental competency. She agreed that her change of opinion came about after an assessment on 22 July 2021 that took place at JNH and lasted for only 50 minutes, following which she prepared her final report dated 26 July 2021. 194 It was put to Dr Ferris that she reversed her opinion based substantially on Ms Rigney’s improved condition at the time she interviewed her on 22 July 2021. Dr Ferris said she also altered her opinion based on the clinical information that Ms Rigney gave her during that assessment. When asked to explain her belief that Ms Rigney was able to provide further truthful information about the stabbing, Dr Ferris said: When I had interviewed her pretty much on every occasion up to that point she had been heavily influenced by what I noted to be perceptual disturbances. Her attention was poor, she was distractible, she was unable to answer questions well and she was irritable a lot of the time. On this assessment I found that she was more able to respond to questions, more able to engage in the interview and there was no evidence of psychotic phenomena. 195 Dr Ferris reiterated that she was more able to pursue lines of questioning that Ms Rigney had previously shut down. Dr Ferris explained that Ms Rigney’s improved engagement in the interview gave her the impression that she was more able to answer questions and provide information regarding the stabbing because she was more able to generally understand and engage in the questioning than she had been previously. 196 It was put to Dr Ferris that she had not recorded anything said by Ms Rigney in the interview on 22 July 2021 that was in any way inconsistent with previous statements she had made. Dr Ferris said: Yes, there is, and that’s why I altered my opinion. I would not have altered my opinion if I did not believe [that] there are inconsistencies between my three previous assessments and [the report dated 26 July 2021]. 197 Dr Ferris was asked about the questions she posed to Ms Rigney and the answers she gave. There was substantial back and forth between Dr Ferris and Ms Rigney’s counsel about how Ms Rigney responded when asked whether she -- 48 of 114 -- [2025] SASC 80 Bampton J 47 remembered certain events on the day of the stabbing, and whether there was any inconsistency between her response during the interview on 22 July 2021 and how she had responded previously. It was repeatedly put to Dr Ferris that Ms Rigney had always reported having no memory of events between her attendance at Cash Converters and the police coming to her house with guns. Dr Ferris asserted that there were inconsistencies in the sense that on some occasions, Ms Rigney had said she could not remember, whereas on other occasions she had been evasive, or refused to engage with questions. 198 Dr Ferris said Ms Rigney on 22 July 2021 answered questions about the period of time around the stabbing that she had not answered previously. It was again put to Dr Ferris there was no inconsistency between the information Ms Rigney provided during the interview on 22 July 2021 and the information she gave Dr Ferris during earlier assessments. Dr Ferris said: As I have previously said, it is to do with the clinical assessment. It is to do with the [non-verbal] communication in the room. It is to do with my extensive knowledge of Ms Rigney and her mental state and the way that she answers questions; the way she does not answer questions or refuses to answer questions and it is purely a change in my opinion based on a [niggling] worry that I had in my three assessments that I have well documented, that she was not giving a full, was not utilising the ability to speak fully and openly about her memory of that period of time. And that’s why I changed my opinion based on my clinical assessment, my clinical experience with Ms Rigney over a long period of time. 199 Dr Ferris maintained that it was Ms Rigney’s presentation in the interview on 22 July 2021 that caused her to change her opinion: It was her ability to speak to that time and speak, specifically, to her lack of recollection of that time as opposed to avoiding the question or refusing to answer the questions which had been the case on previous assessments. Together with my clinical assessment of Ms Rigney. 200 Dr Ferris was referred to her statement in evidence-in-chief that during the interview on 22 July 2021, Ms Rigney’s improved presentation meant that Dr Ferris could “ask specifics … [and] try to catch her out to see whether she was being truthful”. Dr Ferris was asked whether she tricked Ms Rigney into giving answers that were inconsistent with those she had given before. Dr Ferris said a clinical examination is very nuanced and relies a lot on clinical experience, on the questioning, and on what psychiatrists call the countertransference or dynamic within the room, including the non-verbal communication. She said: A. … So the word ‘trick’ her out that I used at that time I guess is just a way of further questioning and investigating her understanding. And I did that by managing to ask her more questions about the time that we have previously discussed and actually get answers to those questions this [time] rather than a blanket ‘I don’t know’, ‘I can’t remember’. Q. I’m sorry. But, in terms of what she could remember, there was no inconsistency in that regard, was there. Between what she told you on 22 July. -- 49 of 114 -- [2025] SASC 80 Bampton J 48 A. You keep using the word ‘inconsistency’. I would say that in my other assessments the questioning was shut down more readily. She said ‘I can’t remember’. Whereas in my most recent assessment I was able to ask these questions more readily and she did engage in those questions. 201 By reference to her report dated 30 April 2021, Dr Ferris said Ms Rigney at this time remembered returning home, sitting and smoking cannabis, whereas in her first assessment, she said she could not remember anything after attending Cash Converters. Dr Ferris also agreed that in her first report, she noted that Ms Rigney denied having a relationship with Maria Luis, whereas by the time of Dr Ferris’ report dated 20 September 2020, Ms Rigney admitted having a relationship with “the lady” and buying cannabis from her. 202 Dr Ferris accepted that the inconsistency between Ms Rigney’s answers regarding her relationship with Maria Luis was apparent by the time she wrote the report dated 20 September 2020. It was put to her that in her second and third reports, she concluded that Ms Rigney was mentally incompetent notwithstanding this inconsistency. Dr Ferris agreed, but said that her opinions were based on many factors. 203 Dr Ferris also noted that Ms Rigney provided information to Dr Nambiar regarding the black backpack, whereas she had denied having a black backpack in her interviews with Dr Ferris. After it was pointed out that Dr Nambiar’s reports of what Ms Rigney said on the topic of the black backpack were not inconsistent with what Ms Rigney had told her, Dr Ferris acknowledged that she had confused Dr Nambiar’s report with that of Dr Furst. She accepted that whilst Ms Rigney discussed the matter with Dr Furst, this could not have influenced her because she did not read his report until after preparing all of her reports. 204 Dr Ferris was referred to her statement in evidence-in-chief that psychiatrists very regularly assess offenders who have acute psychotic symptoms but nonetheless do not satisfy s 269C because there has to be knowledge of the content of the psychotic thought that leads to the behaviour. It was put to Dr Ferris that in the interviews preceding the first three reports, Ms Rigney did not detail any psychotic thoughts at the time of the stabbing. Dr Ferris said: No … it is very [multifactorial] when considering the [s 269C] legislation. It is [multifactorial] in regards to the clinical, in that the clinical assessment that you are doing, in terms of the collateral information, in terms of the questions, in terms of the subconscious response and [non-verbal] communication. It is not always totally to do with the content of the psychotic belief. It can also [have] to do with the thought processes as well. 205 It was put to Dr Ferris that knowledge of the psychotic thought does not need to come from a defendant. Dr Ferris said: In most cases you would get that information from the defendant. On occasions, the collateral information is very clear. They might have been yelling, delusional content right before a behaviour or an offence and that would feed into the information that you have. -- 50 of 114 -- [2025] SASC 80 Bampton J 49 206 It was put to Dr Ferris that in Ms Rigney’s case, knowledge of the content of the psychotic thought was not required for her to reach a conclusion that Ms Rigney was mentally incompetent. Dr Ferris agreed that on balance, in her first three reports, she concluded that Ms Rigney was mentally incompetent despite the poverty of evidence of psychotic thought at the time of the stabbing. She referred to the collateral information she had used, including the videos, and the fact that she had seen her in the AWP very soon after the stabbing. She said her conclusion as to competence was not based purely on her interview with Ms Rigney, during which she did not disclose much information. 207 It was put to Dr Ferris that the nature of the attack could be another factor suggesting that Ms Rigney was incompetent. She reiterated her opinion that frenzied attacks can be carried out by people with personality dysfunction as well as people with psychotic belief systems. Dr Ferris agreed that the nature of the attack was consistent, in her view at the time she prepared her first three reports, with Ms Rigney being psychotic due to paranoid schizophrenia. 208 When asked whether she asserted Ms Rigney had a memory of the stabbing, Dr Ferris said she believes that Ms Rigney is able to speak more freely about what occurred in that period of time. She asserted that on balance, she is of the view that Ms Rigney has a memory of what occurred. She said she formed that opinion based on: … the nuances of the questioning around the time, the clinical presentation in being quite able to speak about other events openly and freely and yet shutting down, refusing to respond to questions in relation to that time period. And I guess also looking at the clinical notes of her ability on the ward as an inpatient where there haven't been any concerns whatsoever about any memory disturbance whatsoever. 209 Dr Ferris agreed, noting that Dr Furst had also agreed, that it was possible Ms Rigney had no memory of the incident because of her psychiatric illness. However, she said it is more likely that Ms Rigney reported having no memory upon realising the trouble she was in. Dr Ferris agreed that she had not expressed this view in her first three reports but said she had documented the limitations of her opinions and her concern that Ms Rigney might be feigning memory difficulty. 210 It was put to Dr Ferris that even if Ms Rigney remembered the stabbing and her psychotic processes at the time, her choice not to disclose that information may be a product of the guardedness aspect of her paranoid schizophrenia. Dr Ferris accepted this possibility but said she did not believe it applied in this case, and that even if it did, that would amount to Ms Rigney withholding information because she understood her mental state, the wrongfulness of her actions, and the consequences of her conduct. 211 It was put to Dr Ferris that Ms Rigney might only have items of memory of the stabbing and that she might be concerned that the memories suggested she was guilty of a crime. Dr Ferris said that Ms Rigney has not discussed this with her but that she did not consider it was a possibility in her case. -- 51 of 114 -- [2025] SASC 80 Bampton J 50 212 Dr Ferris agreed that Ms Rigney’s attendance at Cash Converters and Maria Luis’ house are not inconsistent with her having been mentally incompetent at the time of the stabbing, pointing out that walking along the street and attending to basic tasks is something that psychotic people can do. Dr Furst 213 Dr Furst is a specialist psychiatrist, having obtained his specialist qualification in 2010. He obtained the Advanced Training Certificate in Forensic Psychiatry in 2011 and has been the Executive Director of Mental Health Services and SA Prison Health Service at the Central Adelaide Local Health Network since 2021. He has experience treating patients at JNH and outpatients in clinics at several South Australian prisons. Dr Furst reported he regularly provides expert psychiatric reports and has given evidence in the Supreme and District Courts of South Australia regarding many issues including mental fitness and competence. Dr Furst’s report dated 2 May 2022 214 Pursuant to s 269WA, Dr Furst interviewed Ms Rigney at JNH for 90 minutes on 2 November 2021 and prepared a report dated 2 May 2022. 215 Dr Furst referred to Ms Rigney’s report that prior to her arrest, she had been subject to a CTO but had not been taking her medication. He said that Ms Rigney reported having mental health problems since she was 16 years old, and that while she had been diagnosed with five disorders, upon being read the symptoms of schizophrenia, she understood that she had had this condition her “whole life”. Dr Furst detailed that she described auditory hallucinations of female voices singing lullabies and male voices whispering, which worsened at night when she felt that they were getting closer, touching her hair and saying her name. He stated that Ms Rigney reported daily command hallucinations to hurt herself, which she tried to ignore but had previously acted upon by stabbing herself in the chest. Dr Furst said that Ms Rigney showed him a scar on her left pectoral region. 216 Ms Rigney reported having been in hospital many times due to her schizophrenia and having been diagnosed with bipolar disorder, BPD, drug-induced psychosis, and split personality disorder. 217 Ms Rigney told Dr Furst she was unaware of any family history of mental illness. Ms Rigney reported that she began smoking cannabis at 14 years old and would buy a bag each pay day to smoke within 20 minutes, and that she smoked three points of methamphetamine every two days, staying awake for three to four days at a time. Ms Rigney denied experiencing paranoia or scattered thinking after using cannabis or methamphetamine and further denied experiencing ‘come down’, withdrawal or cravings after methamphetamine use. 218 Dr Furst recorded that Ms Rigney reported being “raped a lot” as a child. 219 Dr Furst noted in relation to the stabbing that Ms Rigney reported having been smoking cannabis, “chilling out” with her friends and experiencing auditory -- 52 of 114 -- [2025] SASC 80 Bampton J 51 hallucinations, which told her to do “the usual stuff” such as simply to tip a plate over, or to be destructive or disruptive. Ms Rigney told Dr Furst she recalled attending Maria Luis’ house to obtain a bag of cannabis, which she smoked after returning to her own house. She recalled going back to Maria Luis’ house to drop her backpack off, although she did not know why she did so, but could not remember anything that happened subsequent to this until the police entered her home after she had just finished “ripping a bong”. 220 Dr Furst recorded that Ms Rigney denied arguing with Maria Luis, saying that she had simply heard people say to go to her address if you wanted a bag. She spoke of having money from Cash Converters but reported having no memory of how she got home after being at Cash Converters and no memory of the stabbing. Ms Rigney told Dr Furst that she had “no idea” about a knife and that she did not usually carry one with her, although she usually carried scissors to chop cannabis. 221 Dr Furst reported that during his interview of Ms Rigney, she indicated she was aware of both the fact that she had been charged with murder and the allegations upon which the charge was based. He stated that she expressed an intention to plead not guilty because “[she] never done it, [she’s] not capable of doing something like that to somebody”. He noted that she showed some insight into her mental illness and understood that her auditory hallucinations were not real and required treatment with medication. However, Dr Furst’s opinion was that Ms Rigney did not “truly appreciate the effect of her illness on her actions”. He said that while her judgement was “unsophisticated”, there was no sign of “acute impairment”. 222 Dr Furst referred to Ms Rigney’s well-documented history of chronic treatment-resistant schizophrenia characterised by delusions of pregnancy, rape, and ghost infestation, as well as chronic auditory and visual hallucinations. He expressed the view that she likely had chronic symptoms for months or more than a year prior to the stabbing, although her cannabis and methamphetamine use led psychiatrists to diagnose her with drug-induced psychoses. 223 Noting that while there are possibly “alternative explanations” for Ms Rigney’s presentation during the first police interview, Dr Furst stated that the two police interviews make clear that Ms Rigney was “quite psychotic” immediately after the stabbing. He further explained, by reference to Ms Rigney’s reported cannabis use on 7 December 2018 as well as the toxicology report, that Ms Rigney’s lack of focus and uncooperative manner during her arrest could possibly be attributed to drugs superimposed on underlying psychosis. However, his opinion was that Ms Rigney was suffering from chronic paranoid schizophrenia at the time of the stabbing that was “completely independent” of drug use. Dr Furst stated that while Ms Rigney presented with difficulty concentrating or offering sensical answers during the first police interview, she was more focussed during the second police interview. However, in his opinion, she remained psychotic on 8 December 2018. -- 53 of 114 -- [2025] SASC 80 Bampton J 52 224 Dr Furst nonetheless concluded it is “extremely unlikely” that Ms Rigney did not know the nature and quality of her conduct and said she was clearly not completely unable to control her conduct, even if her capacity to control it was diminished as a result of her chronic psychosis, which impairs frontal lobe control and increases impulsive behaviour. He stated that Ms Rigney’s burning of clothing suggests some degree of control over her conduct. 225 Dr Furst said the central issue is whether or not Ms Rigney, as a result of her schizophrenia, was unable to reason about whether her conduct was wrong as perceived by reasonable people. He said he could find no evidence in his assessment of Ms Rigney (noting her account of the stabbing was very limited), in the reports of Dr Nambiar or Dr Ferris, or in the collateral material to indicate that she had acted on some delusional belief arising from her schizophrenia. 226 Dr Furst characterised the early opinions of Dr Nambiar and Dr Ferris as “[appearing] to rely on a presumption of disorganisation rendering her unable to reason about wrongfulness”. However, Dr Furst’s opinion was that whilst Ms Rigney presented as quite disorganised immediately after the stabbing, this does not provide an adequate explanation. He considered there is a “credible alternative explanation” having regard to Ms Rigney’s history of buying cannabis from Maria Luis and conflict with her in the days prior to the stabbing. Dr Furst considered it plausible that Ms Rigney attempted to purchase or purchased cannabis from Maria Luis and that a disagreement occurred during that interaction. He said that if such a disagreement occurred, it is likely that Ms Rigney’s psychotic state would have predisposed her to react in a “paranoid, impulsive and aggressive manner”. Dr Furst stated that in such circumstances, Ms Rigney would have acted on impulse and in a heightened emotional state but nonetheless would have known that her conduct was wrong. 227 Overall, Dr Furst said that he considers this latter explanation to be more likely and therefore cannot be satisfied on the balance of probabilities that Ms Rigney was unable to know the wrongfulness of her actions as a result of her schizophrenia. He concluded his report saying that he could not support a s 269C defence. Dr Furst’s evidence 228 Dr Furst was asked in evidence about Ms Rigney’s understanding and experience of auditory hallucinations. He stated: My recollection is that she had described hearing voices prior to the incident, but she was either not able to or not prepared to describe what happened in that sort of incident in the house and so it was unclear to me whether she had hallucinations at that point in time but certainly she had described them prior to the incident and after, in prison and in hospital. 229 Dr Furst explained that along with hallucinations and delusions, disorganised thought form is another key symptom of psychosis. He described disorganised thought as an inability to move logically from one thing to another; that is, maintain -- 54 of 114 -- [2025] SASC 80 Bampton J 53 a linear train of thought. Dr Furst said there are many ways disorganised thought can manifest, including persons going off on a tangent, talking around a topic for a long time before circling back, suddenly stopping talking without knowing what they were talking about (“thought blocking”), and being “all over the place” in their thinking. 230 Dr Furst also expanded on his opinion that Ms Rigney was not completely unable to control her conduct even though she was likely to have diminished control of her actions due to chronic psychosis: A. … Essentially, when people are psychotic, their ability to inhibit their impulses and control their behaviour is diminished. It’s not absent but it is diminished, and so people with active psychosis are more prone to act impulsively and I think in particular they’re more likely to act in situations where they are afraid and have a sense of fear, which is often paranoia and not a genuine threat but they’ve interpreted something in a threatening way and they’re more likely to react in an impulsive way and people with a particular predisposition, that might be to react violently. Q. Sorry, people with a particular. A. With a predisposition to acting out, they might act violently. So they might be more predisposed to that. Their ability to control their behaviours is reduced. 231 He further explained that in extreme cases, control over behaviour may be “practically absent” or in cases of catatonic forms of schizophrenia, a person might have “very reduced capability” to control their actions, but that this is “pretty rare”. 232 Dr Furst stated that it is very difficult for a person to meet the s 269C(1)(a) test because it is “quite unusual for a person to not know [the nature and quality of] what they have done, the physical act”. His opinion was that the evidence did not support a conclusion that Ms Rigney satisfied s 269C(1)(a). 233 Dr Furst then explained his conclusion in respect of s 269C(1)(c), which he described as “also fairly uncommonly met… [because] it’s a very high bar to meet for someone to be totally unable to control [their conduct]”: … based on my assessment of Ms Rigney, all the material that was available, I thought it was clear that she had some control over her conduct. She clearly had gone to the house, come away from the house, had been to Cash Converters earlier in the day, there were questions about whether or not she had burnt clothing or not and I’m not sure what the [Court’s] determination about whether that occurred or not but all of these things suggested that she had some control over her actions, so again I thought that limb C was not made out. 234 Finally, Dr Furst turned to s 269C(1)(b). He stated that he weighed up the likelihood of two different hypotheses, which he explained in the following terms: … one hypotheses is that she had been there to buy cannabis, there had been some kind of history between them perhaps, that there was some kind of conflict about cannabis or something else that arose between them and that in the course of that, she reacted by using a weapon that she had on her or was nearby or something, reacted angrily and stabbed the -- 55 of 114 -- [2025] SASC 80 Bampton J 54 person and then left. So that’s one hypothesis. There might be others but that was to me seemed one reasonable hypothesis. The other hypothesis was that she had gone there and that there was mental processes that meant that she didn’t know that stabbing a person was wrong, that there was some other, a delusion, you know, a paranoid or a persecutory belief that would override that everyday understanding that stabbing somebody is wrong… Dr Furst noted that there was a gap in Ms Rigney’s report of events between attending Maria Luis’ house to obtain cannabis, going home to smoke it, returning to drop her backpack at the front of the property nearby the Luis home, then the police coming to her house. He referred to Ms Rigney giving an account during the second police interview of being present at Maria Luis’ home and witnessing her being stabbed but explained that “there was no explanation or anything deriving from her psychosis as to why she would be unable to know that stabbing a person was wrong”. 235 Dr Furst said that the issue was “fairly finely balanced” but that “there just wasn’t enough there … to make out [the s 269C] defence” noting that “[he] had to balance that against an alternative hypothesis”. 236 When asked whether there was any evidence of a link between the stabbing and Ms Rigney’s schizophrenia, Dr Furst said that he had only noticed an association, as detailed in her medical history, between her being unwell and engaging in violent behaviour. He said that her behaviour would be consistent with someone who has a predisposition to act aggressively. Dr Furst went on to explain that active psychosis in a person with this predisposition diminishes their control and reduces inhibition of inappropriate behaviour. Dr Furst said he considered this to be a link between Ms Rigney’s mental illness and the stabbing, but he could not find that it went beyond diminished control of behaviour to inability to reason about wrongfulness or complete inability to control conduct. Cross-examination of Dr Furst 237 Dr Furst confirmed during cross-examination that in his opinion, Ms Rigney suffered from chronic treatment-resistant schizophrenia at the time of the stabbing. When asked whether treatment-resistance is evidenced by the fact that the treatment Ms Rigney received during the two years preceding the offence was unsuccessful, he said: That’s certainly an indicator. It’s probably more likely confirmed by the treatment she had post-offence when we know she was in a controlled environment, being monitored, not accessing illicit drugs, then I think you’re much more confident that in fact it’s what we call treatment resistant, which means that the treatment isn’t as effective as it ought to be versus someone who is perhaps poorly compliant with treatment or there are other factors like drug use or something in the community. So the history preceding the incident is informative, the history after the incident I think confirms that. 238 Dr Furst also noted that Ms Rigney reported having ongoing hallucinations prior to the stabbing. He agreed that she had several consistent, delusional beliefs during the period leading up to the stabbing and that there were times Ms Rigney likely had disorganised thinking. -- 56 of 114 -- [2025] SASC 80 Bampton J 55 239 Dr Furst was referred to Prof White’s report, in which he concluded that the concentration of antipsychotic medication in Ms Rigney’s blood taken approximately 12 hours after the stabbing was relatively low but still at a therapeutic level. Dr Furst expressed difficulty with the term “therapeutic level” and explained that Prof White was referring to the concentration being within the average range. He noted that this does not necessarily mean that the concentration was at an effective therapeutic level for Ms Rigney. 240 Dr Furst accepted that prior to the stabbing, Ms Rigney was receiving medication that was not effective in treating her condition. He explained that the dose may not have been high enough or that she may not have responded to the drug she was being prescribed. When asked whether the medication would have been working to some extent, Dr Furst noted that 65 percent of the population experience a significant improvement in their clinical symptoms when treated with most antipsychotic medications, which increases to 75 percent when clozapine is prescribed. He said that while 25 percent of the population will continue to experience significant symptoms no matter which antipsychotic medication they are prescribed, most medications at some level would usually have some effect. Dr Furst also accepted that the effectiveness of antipsychotic medication is reduced by illicit drug use, particularly cannabis and methamphetamine. He agreed that Ms Rigney’s medication not working would have been a significant contributing factor in relation to her conduct on the day of the stabbing. 241 Dr Furst accepted that Ms Rigney falls within the 25 percent of the population that continue to experience significant psychotic symptoms even with clozapine treatment, and that it is extremely likely that she was actively psychotic on the day of the stabbing, noting that the intensity of symptoms varies naturally and depending on factors such as illicit drug use and stress. He agreed that if Ms Rigney had consumed cannabis before the stabbing, it could have exacerbated her psychosis. 242 In respect of the first police interview, Dr Furst said he did not disagree with the proposition that Ms Rigney was likely to have been quite psychotic, saying that her presentation was likely related to a combination of her psychosis, any consumption of drugs, and shock. He said: … the difficulty I have is her presentation the following day was different. So quite often when someone’s been arrested for an incident, you know, and you’ve got that video footage, that is the most useful thing to be able to tell what their mental state was at the time of the offence. The difficulty I have for this case was that her mental state seemed to change quite significantly from that night to the next day and she had admitted that she had been smoking cannabis prior to the police arriving. So that made it very difficult for me to say ‘Well, the mental state that I saw on the video is predominantly due to her psychosis or is it partly due to her psychosis with a large dose of cannabis effect on top’. 243 Dr Furst also accepted that Ms Rigney was quite psychotic at the time of the second police interview, and that she was irritable, smiled inappropriately and incongruently, became guarded, and eventually refused to answer further -- 57 of 114 -- [2025] SASC 80 Bampton J 56 questions. He agreed that Ms Rigney presented with difficulty controlling frustration, which he considered a symptom of ongoing psychosis as distinct from a personality factor. 244 With respect to Ms Rigney stating that she did not believe she had been charged with murder and not understanding the charge, Dr Furst did not accept that this indicated psychosis. He said this appeared more like the normal psychological process of denial but accepted that Ms Rigney’s statements could indicate that she did not understand that she was charged with murder and was perplexed by the allegation. 245 Dr Furst said that the way Ms Rigney engaged in the second police interview, her thought processes, and her behaviour gave him the overall impression that she was psychotic. He said that Ms Rigney appeared more floridly psychotic during the first police interview but there were still signs that she was psychotic during the second police interview. He described florid psychosis as “severe enough as to be readily apparent and also to have had a significant impairment [on the person’s] thinking and behaviour”. 246 Dr Furst was taken to parts of the video of the second police interview. He disagreed with Dr Ferris that Ms Rigney smiling at nine minutes and 29 seconds indicated that she was responding to auditory hallucinations or some other internal process. He noted a small smile at 13 minutes 45 seconds, which he said was “a little more unusual” and “appeared to be more consistent with perhaps an internal process, [a] hallucination”. He also agreed with Dr Ferris that at 19 minutes 51 seconds, Ms Rigney’s behaviour was incongruent and inappropriate, which he thought had contributed to the global impression that she was psychotic. When asked to comment on Ms Rigney responding quickly and acknowledging that she was acting inappropriately, Dr Furst said this conduct may be due to Ms Rigney’s insight into her schizophrenia. He stated that overall, he still tended to agree with Dr Ferris that Ms Rigney was psychotic. 247 Dr Furst accepted that if Ms Rigney had been psychotic at the time of the second police interview, she may have been floridly psychotic at the time of the stabbing. He agreed that the intensity of psychosis can vary and dissipate over months, weeks, days or even hours. Dr Furst said that he has given evidence in some cases that when an acutely psychotic person commits a serious offence (particularly murder), the incident can be such a “shock to the system” that their psychotic symptoms become less pressing on them and the real world becomes more apparent, such that they become better able to differentiate between what is real and what is not real. He accepted that Ms Rigney may have experienced this phenomenon on 7 December 2018. 248 When asked whether Ms Rigney’s schizophrenia was of the paranoid type, Dr Furst said “I think that’s correct”. He explained that while the DSM-IV differentiated between paranoid, disorganised, catatonic or undifferentiated schizophrenia, the DSM-5 does not. Dr Furst expressed the view that the DSM-IV -- 58 of 114 -- [2025] SASC 80 Bampton J 57 was probably more useful in this regard and said that Ms Rigney has “clear features” of both the paranoid and disorganised forms of schizophrenia. He noted that disorganised schizophrenia is commonly associated with poor response to treatment, while people with pure paranoid schizophrenia “often respond quite well to conventional antipsychotics and … don’t need clozapine.” 249 Dr Furst also agreed that the stabbing being linked to a drug-related conflict is not inconsistent with Ms Rigney being psychotic at the time. He said that the conflict could “potentially” have assumed great significance in Ms Rigney’s mind because of her abnormal thinking processes such as hallucinations, delusions or disordered thoughts. For example, Dr Furst agreed that Ms Rigney may have taken the view that Maria Luis was persecuting her because she wasn’t prepared to supply her with cannabis. However, he explained further: … I guess the key question there is: is that a normal belief based on her previous interactions and perfectly rational? Is it a slightly overvalued idea, which a normal person might have but also a person with schizophrenia might have, which is that it’s kind of still realistic but, you know, perhaps a bit overdone and that could be based on, again, her previous interactions, perhaps her perception or slight misperception of those previous interactions and then the third option which is where someone’s actually, frankly, delusional and has a fixed false belief. … about a person which isn’t based on reality, it’s based on the psychotic process within their own head, yep. 250 While Dr Furst agreed that Ms Rigney may have considered that Maria Luis had treated her unfairly and given that idea “a prominence that it may not have deserved”, he did not accept that it was more likely than not that Ms Rigney would have reacted psychotically if she had been rebuffed by Maria Luis on the day of the incident. He said: I don’t think you can be that clear that it’s because of the psychosis, it’s because of a paranoid interpretation of the events. Certainly people who are psychotic will have a general predisposition, as I said, more fearful, more paranoid, more impulsive, all of those things and so certainly within that context she might have felt like she was being rejected unfairly, but that’s also part of normal day-to-day interaction. That doesn’t necessarily mean it was the psychosis which caused her to react. 251 Dr Furst agreed with the proposition that the attack on Maria Luis was frenzied but said that a person in a heightened emotional state could react to a situation in a frenzied manner without being psychotically driven, particularly a person who might be angry about being refused cannabis in circumstances where there might be a perception that the refusal is unfair. Dr Furst noted that this would particularly be the case if there were a sense of the refusal being related to race. 252 Dr Furst agreed that when determining whether conduct is psychotically driven, it is necessary to consider what might have precipitated the incident, the nature of the perpetrator’s conduct and the explanation offered by the perpetrator. When asked whether Ms Rigney inflicting 34 stab wounds in response to Maria Luis refusing to supply her with a small bag of cannabis suggested a psychotic motive, Dr Furst stated that he was unable to draw this conclusion in -- 59 of 114 -- [2025] SASC 80 Bampton J 58 circumstances where he did not know what had occurred in the interactions between Maria Luis and Ms Rigney: … So if it was assumed that the victim was, you know, peaceful, polite, calming in their approach, a perfectly reasonable person and the attack occurred seemingly out of nowhere, that would certainly raise your concern that it was more likely to be driven by what’s happening inside the person’s head rather than the interaction with the person. The converse to that is if the interaction becomes heated, who knows what is said, then that triggers various emotional reactions in people. So we don’t know, or I don’t know, what occurred in that interaction. He agreed that the nature of the attack is “perhaps suggestive” of a psychotic motive but also suggested the history of conflict between Maria Luis and Ms Rigney might suggest a non-psychotic motive. He further noted that violence is commonly associated with drugs, drug deals and drug debts. 253 Dr Furst reiterated that it is very rare for a person to satisfy s 269C(1)(c): I think it’s because of the way that test is framed, that they’re sort of wholly unable, you know, totally unable to control and I think the issue there is that of course in a moment, any person who has a high emotional state might, what people might colloquially call lose control. The reality is even in those states, people do have some measure of control. The issue is they choose to, it’s not really a conscious choice, but it’s an allowance of their [emotions] to take over and do those actions. So I think that there is always some measure of control there, otherwise any person might have a momentary loss of control and be considered mentally impaired. He gave examples of where the test might be satisfied, including a person with psychomotor epilepsy having a fit, a person waking up from anaesthetic in a delirious state, or a person in a state of catatonic excitement. Dr Furst did not consider that Ms Rigney was in the latter state because catatonic excitement results in a person being “highly activated, highly disorganised in their behaviour, often very hard to communicate with [and] highly irritable” but also results in less purposeful activity than inflicting 34 stab wounds, which he described as “directed. It’s trying to hurt somebody”. 254 Dr Furst said it was “theoretically possible but not terribly likely” that the account given by Ms Rigney to police regarding another person stabbing Maria Luis was produced by her schizophrenia. He explained that this could occur only if Ms Rigney had a delusional memory, which is “pretty rare”, or a visual hallucination of someone else stabbing Maria Luis in combination with delusions. Dr Furst also agreed it was possible that Ms Rigney was in a psychotic state at the time such that she had no memory of the stabbing, then provided a story to exonerate herself upon being charged with murder. However, he said it was possibly more likely that Ms Rigney recalled some aspects of the stabbing and appreciated that she might be in trouble, which led her to fill the gaps in her memory with an exculpatory story. 255 Dr Furst accepted that child sexual abuse can affect memory of the abuse due to a combination of the incidents being “sort of blacked out” and the person -- 60 of 114 -- [2025] SASC 80 Bampton J 59 consciously and unconsciously avoiding thinking about the trauma. He agreed that both child sexual abuse and an incident such as stabbing Maria Luis could generate PTSD. Dr Furst also accepted that PTSD can be comorbid with schizophrenia and affect memory either on its own or in conjunction with the effect of psychosis. 256 Dr Furst summarised his opinion in the following terms: A. … I think it’s absolutely certain that she has psychosis, I think she had active psychosis, the question for me was whether she was so floridly psychotic that she can’t remember what happened and something internal triggered this offence and, on the other hand she was psychotic but not floridly psychotic at the time of the offence and there was something else that happened in that interaction and then she’s had an emotional reaction or behavioural reaction which was probably exacerbated by her schizophrenia, but not to the point of being mentally incompetent. Q. So you maintain your view that she does not have the defence available to her. A. I don’t think I can say it’s more likely than not. I’m afraid I’m sort of - it’s very close, but certainly I don’t feel like there’s enough there to say that I’m more confident that it’s more likely than not. Prof Coyle 257 Prof Coyle is a forensic and clinical psychologist and psychopharmacologist. He is the principal consultant to Australian Forensic and Personal Injury Consultants Pty Ltd. Prof Coyle was conferred a B.A. (Hons) by the University of Sydney in 1971 and a PhD by La Trobe University in 1975, and was then awarded a postdoctoral fellowship in 1976. 258 Prof Coyle said he has given evidence in District and Supreme Courts in New South Wales, the High Court in the Solomon Islands, the High Court in New Zealand, District and Supreme Courts in Queensland, and Supreme and District Courts in South Australia, including the Court of Criminal Appeal.6 He gave evidence he has been involved in about 20 criminal matters concerning mental competency over the past seven years. Prof Coyle said in evidence he is involved in research work, particularly in the interaction between law and science, law and psychology, law and psychopharmacology, and law and human factors engineering. Prof Coyle’s report 28 July 2022 259 Prof Coyle provided a report dated 28 July 2022 to Ms Rigney’s solicitors following his two-hour assessment of her. Prof Coyle reported: It is incontrovertible that Ms Rigney had, at the very least, exhibited PTSD, Antisocial Personality Disorder and Schizophrenia prior to the stabbing of Ms Maria Luis that took place on 7/12/2018. The conjoint operation of these disorders resulted in severe mental impairment at the material time. 6 Prof Coyle gave evidence in R v Bromley [2018] SASCFC 41 regarding the reliability of an eyewitness who suffered from schizophrenia. -- 61 of 114 -- [2025] SASC 80 Bampton J 60 He further reported that: There is no doubt that Ms Rigney’s inability to recall events on the night in question can be clinically explained by the conjoint operation of Dissociative Amnesia and Schizophrenia. Prof Coyle concluded: At the material time, it is my opinion that it is more likely than not that Ms Rigney was suffering mental impairment due to the conjoint operation of her complex psychopathology. In my opinion, this precluded her from knowing whether the conduct was wrong and/or she was totally unable to control the conduct. 260 By reference to Ms Rigney’s medical and psychiatric reports, Prof Coyle said Ms Rigney has an extensive history of poorly managed and misdiagnosed schizophrenia from when she was 16 years old. For example, Prof Coyle noted that she was first admitted to mental health services at the age of 17, in July 2017, following concerns “vis-à-vis” her mental health at 30 weeks’ pregnant. Prof Coyle commented that during this admission, there was clear evidence of psychosis with auditory and visual hallucinations against the background of a delusional belief system. He also referred to her presentation at the Modbury Accident and Emergency Department on 2 April 2018, following which she was diagnosed with a drug-induced psychosis. Prof Coyle noted that Ms Rigney’s most recent diagnoses include paranoid schizophrenia, bipolar affective disorder, complex PTSD, and antisocial personality disorder against a background of drug-induced psychosis. 261 Prof Coyle stated that the psychiatric reports of Dr Nambiar, Dr Ferris, and Dr Furst “[glossed] over the sexual abuse inflicted upon Ms Rigney and the sequelae thereof”. He referred to this as “a significant lacuna having regard to the well-established consequences of sexual abuse vis-à-vis mental health and brain damage”. 262 Prof Coyle reported that during his assessment of Ms Rigney, she displayed unusual thought patterns, albeit no delusional content. He said there was clear evidence of visual, auditory and olfactory hallucinations, and that he established a good rapport with her: In fact, she opined that she felt more comfortable talking to me than any of the psychiatrists she has dealt with. At the end of my assessment session with her she approached the nursing staff and asked them to give me a copy of a document she had written outlining the child sexual abuse she was subjected to. It is of some note that she had not made this available to anyone else outside the nursing staff prior to my assessment. 263 Ms Rigney informed Prof Coyle that she found herself ruminating over what happened when she was sexually abused or raped and wondering what was going to happen “vis-à-vis” her criminal trial. He said that she reported having nightmares intermittently, which revolved around the rapes she was subjected to. He said she also reported flashbacks of being raped, which were frequently -- 62 of 114 -- [2025] SASC 80 Bampton J 61 associated with derealisation, as well as anxiety attacks or paranoid feelings, which Prof Coyle said were associated with thinking about her criminal trial and exposure to stimuli (especially smells or sounds) and memories related to being raped. Prof Coyle reported that Ms Rigney stated she tries to avoid memories of being raped but is largely unsuccessful. She reported this made her feel frustrated, depressed and angry, and that she engaged in extensive recreational substance use to block out the abuse, including cannabis from the age of 14, amphetamine, and methamphetamine. Ms Rigney told Prof Coyle that she was smoking $50 worth of cannabis per week at the time of the stabbing. 264 Ms Rigney told Prof Coyle that she hears voices, sees ghosts who instruct her what to do, and has olfactory hallucinations of foul smells. She reported that the voices sometimes tell her she is no good and to hurt herself, but she is able to resist them. The ghosts are vague and ill-formed, but she has seen the Kardachi Man on a few occasions. She reported that the devil talks to her, usually at night, but she cannot understand what he is saying. 265 Under the heading “Clinical impressions”, Prof Coyle reported Ms Rigney was persistent in stating that she could not remember anything relevant to the stabbing, except vague recollections of attending Cash Converters to get money and dropping her bag off, although she had “no idea why [she] did this”. He reported that her next memory was the police pointing guns at her and that she denied memory of being interviewed by police, insisting “I really don’t remember what happened but I know I was sick at the time”. Prof Coyle stated her recollections are in accord with her presentation in the first police interview, during which she was clearly cognitively disorganised and/or experiencing hallucinations. Prof Coyle said he formed the view that Ms Rigney was “genuine vis-à-vis the history she [had] recounted and her symptoms”, and that he could not detect any evidence of lying. 266 Prof Coyle administered psychometric tests and reported that Ms Rigney’s results were highly indicative of PTSD. Prof Coyle said he agreed with Prof White’s opinion that “psychotic effects due to the combination of cannabis and methamphetamine at the time of the incident … seem unlikely”, noting his own expertise in psychopharmacology. 267 Prof Coyle noted various effects of child sexual abuse, including increased risk of psychological/psychiatric disorders, and remarked that none of the psychiatrists had commented on the undeniable fact that the child sexual abuse Ms Rigney suffered was overwhelmingly likely to be fundamental to the development of her schizophrenia. He further stated it was beyond doubt that the sexual abuse was instrumental in the development of her conduct disorder (as it then was), antisocial personality disorder, and PTSD. He opined that it was completely indisputable that Ms Rigney would have more likely than not engaged in significant substance abuse as a direct consequence of being sexually abused as a child. To emphasise this, he pointed to a search on Google Scholar for “child sexual abuse and drug use”, which returned 1.9 million research articles. -- 63 of 114 -- [2025] SASC 80 Bampton J 62 268 Prof Coyle then went on to discuss memory and trauma. He stated that the DSM-5 defined dissociative amnesia as the inability to recall important autobiographical information that is inconsistent with normal forgetting. He said dissociative amnesia is a rare presentation with a prevalence of 0.2 percent in the population, as is schizophrenia with a presentation of some 0.3 to 0.7 percent. He stated although there is still a debate about dissociative amnesia being caused by trauma generally, there is “ungainsayable evidence that [dissociative amnesia] does occur in cases where patients have comorbid schizophrenia, let alone other comorbid conditions such as [those] Ms Rigney had”. 269 Prof Coyle stated it is well-established that child sexual abuse causes brain damage and results in loss of autobiographical memory. Again, he referred to a search on Google Scholar for “child sexual abuse causing brain damage and autobiographical memory loss” returning in 22,400 articles. He stated this memory loss continues into adulthood and that it has been demonstrated that child sexual abuse can impact autobiographical memory in respect of subsequent traumatic experiences, such as the stabbing and Ms Rigney’s police interviews. Prof Coyle reiterated that the failure of the psychiatrists to comment on the pivotal issue of well-established clinical explanations for Ms Rigney’s inability to recall the day of the stabbing is of some note. 270 Prof Coyle concluded his report asserting that the behaviour Ms Rigney engaged in on the night of the stabbing was caused by her comorbid psychopathology involving paranoid schizophrenia, PTSD, and possibly bipolar affective disorder. He contended it is likely that Ms Rigney also suffered brain damage as a consequence of child sexual abuse inflicted upon her, which must also be considered. He noted the effect of PTSD and brain damage arising from child sexual abuse interacting with trauma and dissociative amnesia, all of which are incontrovertible in survivors of child sexual abuse, on Ms Rigney’s psychopathology at the time. He stated the failure of Dr Furst, Dr Ferris, and Dr Nambiar to comment on this is of some note. Prof Coyle said there is no cogent, objective evidence proving that it is more likely than not Ms Rigney can recall the events of the day. He stated, having regard to her history and the police interviews, the most reasonable explanation for the behaviour Ms Rigney engaged in on the day of the stabbing was her comorbid psychopathology over which she had no control. He said that in is his opinion, it is more likely than not that Ms Rigney was “suffering mental impairment due to the conjoint operation of her complex psychopathology”. In his opinion, this precluded her from knowing whether her conduct was wrong and/or she was totally unable to control the conduct. Prof Coyle’s consideration of Dr Nambiar’s reports 271 Noting Dr Nambiar’s initial view, as expressed in his report dated 26 March 2020, that Ms Rigney had the mental incompetence defence available to her, Prof Coyle is critical of the fact that Dr Nambiar changed his opinion in his report dated 20 July 2020 after being asked to consider matters in the DPP letter. Prof Coyle said: -- 64 of 114 -- [2025] SASC 80 Bampton J 63 I think it necessary to note that I have not been involved in any case where an expert has been asked to consider possible inferences based on one interpretation of behaviour in such a way as was iterated in the letter from the Director of Public Prosecutions. The way in which the propositions dealing with possible inferences that might be drawn vis-à-vis the defendant’s mental competency are framed, raises a very real prospect of unconscious bias being brought into play through well-established processes of cognitive heuristics. (Emphasis in original) He referred to what he characterised as seminal research and said that, in his view, the objectivity of Dr Nambiar’s opinions must have been “unconsciously and adversely affected” by the way the questions in the DPP letter were framed. 272 Prof Coyle also criticised Dr Nambiar for not considering the issue of dissociative amnesia, let alone its interaction with schizophrenia and PTSD arising from child sexual abuse, and for not commenting on post-event contamination of memory caused by repeated questioning of Ms Rigney. Prof Coyle’s consideration of Dr Ferris’ reports 273 Prof Coyle also suggested that Dr Ferris’ repeated questioning of Ms Rigney during her interviews raises the issue of post-event contamination of memory, which he noted is not addressed by Dr Ferris. 274 Prof Coyle referred to the report of Dr Ferris dated 26 July 2021, wherein she noted that Ms Rigney’s ability to respond to questions and provide answers had improved and that she engaged well in the interview, ultimately concluding (for the reasons earlier explained) that Ms Rigney did not have the s 269C defence available to her, contrary to her initial view. Prof Coyle commented: On what basis can it be inferred that because Ms Rigney’s capacity to recall events may be more accurate than when she was first interviewed that this more likely than not affects knowledge of her psychotic state at the material time? The short answer is that it cannot, in my opinion. (Emphasis in original) Prof Coyle’s consideration of Dr Furst’s report 275 Prof Coyle referred to Dr Furst’s report of 2 May 2022, wherein he stated that he believed Ms Rigney was suffering from chronic paranoid schizophrenia at the time of the stabbing that was completely independent of any effect arising from drug use. Prof Coyle said that in contradistinction, Dr Furst expressed the view that Ms Rigney’s presentation during the first police interview was due to the effects of drugs superimposed on her chronic psychosis. 276 Prof Coyle then stated this conclusion is at odds with the opinion of Prof White, who acknowledges that Ms Rigney’s drowsiness could be attributable to cannabis use but also posits other reasonable explanations, including sleep deprivation. Prof Coyle argued that Prof White’s opinion is to be preferred to that -- 65 of 114 -- [2025] SASC 80 Bampton J 64 of Dr Furst when it comes to issues of psychopharmacology because of his vast experience and specific expertise in the area. 277 In response to Dr Furst’s statement that, noting Ms Rigney’s account of the stabbing was very limited, there was no evidence that she was acting on a delusional belief arising from her schizophrenia, Prof Coyle said: … it might be asked how would cogent evidence of Ms Rigney acting on some delusional belief system be obtained when she was suffering from Dissociative Amnesia which interacted with her Chronic, [Treatment-Resistant] Paranoid Schizophrenia, PTSD – as well as Bipolar Affective Disorder according [to] Dr Ferris – and the sequelae of child sexual abuse? Prof Coyle then noted the possibility of Ms Rigney having had a flashback with derealisation at the time of the stabbing such that she could not distinguish fantasy from reality, which would have “by definition” rendered her mentally incompetent. 278 Prof Coyle considered that Dr Furst displayed unconscious allegiance bias, confirmation bias and/or framing bias when he concluded that he could not state that “it is more likely than not that [Ms Rigney] was unable to know the wrongfulness of her actions as a result of her schizophrenia”. Prof Coyle said that in his view, Dr Furst’s failure to consider all the seminal elements of Ms Rigney’s psychopathology at the time should be considered fatal to acceptance of his opinions. Dr Nambiar’s report dated 10 August 2022 responding to Prof Coyle’s report 279 Dr Nambiar stated in his report dated 10 August 2022 that Prof Coyle’s opinion relies heavily on details provided by Ms Rigney to the authors of the psychiatric reports. He pointed out that Prof Coyle does not appear to have satisfied himself that those details were in fact correct and as to Ms Rigney’s capacity to recall those details. Dr Nambiar argues this is important because Prof Coyle’s report focuses largely on the issue of Ms Rigney’s capacity to remember events surrounding the stabbing. 280 Dr Nambiar pointed out only one paragraph of Prof Coyle’s report is devoted to Ms Rigney’s psychotic symptoms and stated that Prof Coyle makes no attempt to ascertain a history of psychotic phenomenology, which would have formed the basis upon which a diagnosis of schizophrenia can be made. Dr Nambiar emphasised it is important to note that schizophrenia is one of the primary diagnoses and that in terms of making an assessment under the mental impairment provisions of the CLCA, ascertaining first that Ms Rigney has a mental impairment is of primary consideration. 281 Dr Nambiar said Prof Coyle places considerable emphasis on PTSD. While Dr Nambiar acknowledged that Ms Rigney undoubtedly has experienced trauma in her life, he pointed out it is extremely rare for it to take precedence over the cognitive effects of schizophrenia and intoxication. He stated the notion that child sexual abuse causes brain trauma is only speculative and unproven. -- 66 of 114 -- [2025] SASC 80 Bampton J 65 282 Dr Nambiar stated Prof Coyle’s search for possible aetiologies of schizophrenia, which focus largely on environmental factors and personal experiences whilst dismissing a biological aetiology in the absence of known family history, shows a lack of appreciation of schizophrenia. He pointed out that schizophrenia can occur in some individuals without obvious aetiology, saying that the search for one in circumstances where a diagnosis has already been made by several experienced psychiatrists is unnecessary and demonstrates a lack of clinical experience. 283 Dr Nambiar contended Prof Coyle appears to subscribe to the theory of dissociative amnesia as an explanation for Ms Rigney’s inability to recall events on the night of the stabbing without considering alternatives, such as the effects of chronic psychosis on brain function, intoxication, wilful denial, or avoidance. Further, Dr Nambiar stated that Prof Coyle simply speculated on Ms Rigney’s lack of memory based on case studies rather than taking into account alternative explanations and information. Dr Nambiar refutes Prof Coyle’s criticism that his altered opinion was in any way influenced by the DPP letter and pointed out that his opinion was based purely on clinical interview, notes, and factual information including, significantly, the video of the second police interview. 284 Dr Nambiar contended Prof Coyle places too much emphasis on the issue of dissociative amnesia and appears to have formulated Ms Rigney’s case in the context of a trauma model rather than considering the fluctuating course of schizophrenia, the possible effects intoxication and chronic substance use, or wilful denial or avoidance. Dr Nambiar said the absence of recall of details of the stabbing and the lack of evidence of any specific psychotic phenomenology linking to the stabbing makes it difficult to determine if Ms Rigney’s mental impairment gave rise to the conduct. Dr Ferris’ report dated 15 August 2022 responding to Prof Coyle’s report 285 Dr Ferris pointed out that Prof Coyle documented that she had on three occasions diagnosed Ms Rigney with bipolar affective disorder. Dr Ferris said that she had referred to a previous diagnosis of bipolar affective disorder, but had never made such a diagnosis herself. Dr Furst’s report dated 22 August 2022 responding to Prof Coyle’s report 286 Dr Furst characterised Prof Coyle’s report as “highly problematic in almost every respect and of little value in re-evaluating [his] own opinion and thought process”. Dr Furst said: It is difficult to know where to begin with such a report and it would take an inordinate amount of time to address all of the issues with it, not the least is that of a psychologist offering an opinion on the effect of Schizophrenia and the interaction with mental competence. 287 He reported that Prof Coyle “rightly” noted Ms Rigney’s diagnosis of schizophrenia. He further regarded Prof Coyle’s opinions that Ms Rigney is highly -- 67 of 114 -- [2025] SASC 80 Bampton J 66 likely to suffer from PTSD, and that it was unlikely that psychotic effects at the time of the stabbing were the result of drug use, as uncontroversial. He noted that all reporting psychiatrists supported a primary diagnosis of schizophrenia that had arisen independent of drug use. 288 Dr Furst rejected Prof Coyle’s suggestion that his report contradicts the toxicology report. He stated that his opinion is that Ms Rigney’s psychosis arises from her schizophrenia independent of drug use, although it is possible that she was also drug-affected at the time of her arrest. Dr Furst pointed out that Prof Coyle fails to address matters consistent with this conclusion including the fact that Ms Rigney did not appear drowsy in CCTV footage of the attendance at [Service SA] prior to the stabbing, Ms Rigney’s self-reports of using cannabis before the arrival of police, the likelihood of her having used cannabis to cope with the stress and trauma of the stabbing, and the lack of evidence to support Prof Coyle’s conclusion that Ms Rigney was sleep deprived. 289 Dr Furst stated there is no evidence to support Prof Coyle’s suggestions that any burning of clothing by Ms Rigney may have been the result of frank psychosis or associated delusional beliefs. 290 In response to Prof Coyle’s claim that there was no foundational basis for Dr Furst’s opinion regarding ss 269C(1)(a) and (c), Dr Furst said: My opinion is based on extensive experience in dealing with patients suffering from schizophrenia and that there are very few patients who ever meet [269C(1)(a)] for a mental incompetence defence. 291 Dr Furst explained that for Ms Rigney to meet s 269C(1)(a), her mental impairment would have to have rendered her unable to know that she was stabbing a person, something that is “exceedingly rare”. He stated that there is also ample evidence that Ms Rigney had some degree of control over her conduct; that is, she was not totally unable to control her conduct. 292 Further, Dr Furst noted Prof Coyle’s criticism of his conclusion that there is no evidence to indicate that Ms Rigney’s schizophrenia had directly caused an inability to reason about the wrongfulness of her actions. Prof Coyle said Dr Furst concluded that Ms Rigney “hence has mental competency [and] explicitly completely ignores other conjoint elements of the mental competency defence”. In response, Dr Furst said: 1. his understanding was that for s 269C(1)(b) to be met, the person’s inability to know the wrongfulness of their actions must stem from a mental impairment; 2. his report made no claim Ms Rigney was mentally competent. Rather, he stated that there was not enough evidence available for him to be confident that she was unable to know the wrongfulness of her conduct and that there -- 68 of 114 -- [2025] SASC 80 Bampton J 67 are other explanations for her actions, including anger at being refused cannabis; and 3. his opinion was framed by the understanding that mental competency is presumed, that mental incompetence must be proved on the balance of probabilities, and that the ultimate issue is for the Court. 293 Dr Furst regarded Prof Coyle’s suggestion that Ms Rigney may have been experiencing a flashback with derealisation that interacted with schizophrenia as not supported by any evidence. He said that even had this happened, it does not necessarily follow that Ms Rigney was mentally incompetent. Prof Coyle’s evidence 294 Prof Coyle said he has dealt with people suffering from schizophrenia hundreds of times, including during his postdoctoral fellowship working in a psychiatric hospital for one year, in his clinical practice, and when conducting forensic assessments in prisons. He says that he has diagnosed schizophrenia repeatedly, and that he has been able to do so when it was not picked up by psychiatrists or other psychologists. 295 Prof Coyle said he interviewed Ms Rigney for two hours on 20 June 2022 and formed the opinion that she was being as honest as she could, although she had virtually no memory of a large part of events surrounding the stabbing and only limited memory of other parts, which he described as autobiographical memory loss. He stated that autobiographical memory is “very, very profoundly affected by child sexual abuse” and that it has an organic impact on the brain as well. He referred to Google Scholar search parameters “child sexual abuse causing brain damage” and the retrieval of 101,000 research articles. He said this brain damage has a particular impact on memory and that it can flow on to other traumatic situations. Prof Coyle also stated that the interaction between cannabis, child sexual abuse, and schizophrenia is profound. 296 Prof Coyle formed the opinion that Ms Rigney was grossly psychotic on the day of the stabbing based on the first police interview, in which she is staring off into the distance and “probably seeing things”. He agreed she appeared more lucid during the second police interview but said that this was not inconsistent with her being in a psychotic state at the time of the second police interview, as psychosis can wax and wane, and in any event, some people who are psychotic can appear remarkably normal. 297 When asked about Ms Rigney telling police she attended Maria Luis’ home and witnessed her being stabbed by a black man, Prof Coyle said if Ms Rigney had described witnessing a Martian flying down, he would not have been surprised. He believed that her behaviour was indicative of her still being psychotic, including having a delusional belief system. He said she might have been trying to make sense of things in her own fractured way, which is not uncommon. He -- 69 of 114 -- [2025] SASC 80 Bampton J 68 also suggested that the story may be the product of confabulation, which he described as not sinister but, rather, completely involuntary. 298 Prof Coyle was asked whether a person’s memory of events varies following a psychotic episode or during a psychotic episode. He said: Yes, you have a problem here in that because of her underlying PTSD and the dissociative amnesia that is consistent with PTSD and subsequent trauma you would expect that her memory would have been grossly affected [by] anything associated with trauma on the night in question, but then there can be periods afterwards where there can be flashes of memory, some recall that will happen from time to time. Prof Coyle was asked to explain the basis of his opinion that Ms Rigney was suffering from dissociative amnesia. His answer was, “[b]ecause it is very likely to occur in connection with trauma cases following child sexual abuse”, and that “all things considered, [it is] the most effective scientifically validated explanation for her inability to be able to recall significant if not all aspects of the night in question”. Prof Coyle said that while amnesia can occur in a person suffering psychosis as a consequence of schizophrenia, it is much more likely when they have comorbid PTSD. 299 Prof Coyle reiterated his conclusion that at the time of the stabbing, Ms Rigney was suffering a mental impairment due to the conjoint operation of her complex psychopathology such that she did not know that her conduct was wrong and/or was totally unable to control her conduct. When asked to explain the basis of the opinion that she did not know the wrongfulness of her conduct, he replied, “[s]he was psychotic. By definition, psychosis means a loss of contact with reality”. He also said that his opinion that she was totally unable to control her conduct relied on the frenzied nature of the stabbing. He stated that frenzy or very rapid movement is typically associated with inability of a person to know and/or control what they are doing. 300 Prof Coyle then turned to the reports of Dr Nambiar, Dr Ferris, and Dr Furst, and criticised Dr Nambiar for failing to include scientific citations in his report. With respect to Dr Nambiar changing his opinion on Ms Rigney’s mental competence following consideration of the matters raised in the DPP letter, Prof Coyle again referred to asserted cognitive biases. When it was pointed out that Dr Nambiar had also been provided with the video of the second police interview at the time he received the letter, Prof Coyle maintained that there was still no basis for Dr Nambiar to have revisited his opinion because in his view, she was still psychotic at that time. 301 When asked whether it would make any difference to his opinion if Ms Rigney were to have some memory of the stabbing, Prof Coyle said it would not because she would still have been psychotic. He said that if she provided information, he would regard it with grave suspicion and would need to check it against collateral information. Prof Coyle reiterated Ms Rigney genuinely believed what she was telling him at the time he interviewed her. -- 70 of 114 -- [2025] SASC 80 Bampton J 69 302 Prof Coyle then referred to a logical inconsistency in Dr Ferris changing her opinion on mental competence while still remaining of the view that Ms Rigney was likely to have been experiencing psychotic symptoms at the time of the stabbing. 303 Prof Coyle characterised Dr Furst’s suggestion that any burning of clothing by Ms Rigney would suggest that she had a degree of control over her conduct as “risible” and “capable of provoking uproarious laughter”. 304 Prof Coyle was taken to the comments made by Dr Nambiar about his report. Prof Coyle said that Dr Nambiar states without any knowledge that his clinical interview: … focuses predominantly on symptoms of post-traumatic stress disorder with only a paragraph devoted to psychotic symptoms and no attempt to ascertain a history of psychotic phenomenology, which would have formed the basis upon which a diagnosis of schizophrenia can be made. Prof Coyle said he reviewed the extensive medical records dealing with the diagnosis of paranoid schizophrenia, and that he only devoted one paragraph to psychotic symptoms because that was all that was necessary to indicate his agreement with the diagnosis. He said he spent a lot of time on PTSD symptoms because Dr Ferris, Dr Nambiar, and Dr Furst had glossed over this issue. He repeated that in this matter, the effects of PTSD and its interaction with schizophrenia cannot be separated. In response to Dr Nambiar’s statement that “it is extremely rare for [trauma] to take precedence over the cognitive effects of schizophrenia and intoxication”, Prof Coyle denied saying that PTSD takes precedence over schizophrenia. 305 In relation to Dr Nambiar’s comment that “the issue of [child] sexual abuse causing brain trauma is only speculative and unproven”, Prof Coyle said Dr Nambiar “should be invited to actually read some research literature” and, again referred to a search he conducted on Google Scholar. In relation to Dr Nambiar’s comment regarding Prof Coyle’s search for aetiology being unnecessary and demonstrative of a lack of clinical experience, Prof Coyle said: I’m perilously close to finding myself unable to use sober words to respond, so I’ll do my best. That argument demonstrates a lack of knowledge of the scientific and clinical literature which the Australian and New Zealand College of Psychiatrists has explicitly stated that psychiatrists shall demonstrate their experience and knowledge in current peer reviewed literature. Dr Nambiar has not done that. Prof Coyle said Dr Nambiar has not referred to any scientific literature and without doing so, it is simply wrong for Dr Nambiar to accuse him of being purely speculative. 306 Prof Coyle was asked about Dr Nambiar’s comment that he subscribed to the theory of dissociative amnesia as an explanation for Ms Rigney’s inability to recall -- 71 of 114 -- [2025] SASC 80 Bampton J 70 events surrounding the stabbing without regard to other alternatives. Prof Coyle said he considered alternatives such as wilful denial or avoidance, but stated: If one accepts, as everyone has done, that she is suffering from chronic paranoid schizophrenia, then there can be no question of wilful denial or ignorance because of the word ‘wilful’. She did not have the capacity, the mental capacity, to engage in wilful behaviour because that word implies knowing what she was doing. It is completely inconsistent with a diagnosis of paranoid schizophrenia, which she had had for years before this event. Prof Coyle continued, saying: Again, in simple terms, we’re talking – and very pragmatic terms, we’re talking about a person who, by definition, suffering from paranoid chronic schizophrenia is not in contact with reality. It is that simple. There can be nothing simpler. We are all agreed that she suffered from chronic paranoid schizophrenia at the time. That’s not an argument. It must proceed from that, but in conjunction with the problems, the interactive, the synergistic problems caused by chronic post-traumatic stress disorder that she was not capable of being in contact with reality at that time. It must be proceed from that. There is no other logical, scientific or clinical explanation. 307 Prof Coyle said he takes issue with virtually all of Dr Nambiar’s concluding views. Prof Coyle disagreed that he places too much emphasis on dissociative amnesia and explained he refers to it in the context of it being “massively associated with child sexual abuse”. He went on: I’ve referred to a journal for goodness gracious sake, the psychiatric journal precisely on trauma and dissociative amnesia that Dr Nambiar, Dr Ferris and Dr Furst would appear to be ignorant of. They would appear to be ignorant of, or at least choose not to comment on the well-established scientific relationship and clinical relationship between dissociative amnesia and trauma. This is not fantasy. This is not speculation. This is fact. 308 He contended that Dr Nambiar deliberately chooses to be silent on the issue of child sexual abuse causing drug abuse. When I asked why he thought it was a deliberate choice, he said: My view there is simple. I have iterated all those facts. I put numerous footnotes to scientific articles in my initial report. He had the opportunity of reading that. I presume he read it with some degree of care and skill. If he had read that, then he would have realised that there was a wealth of scientific literature. He ignores it. He just doesn’t say anything about it. … As to why he chose not to say anything, I don’t know. 309 In relation to Dr Nambiar’s comments that the absence of recall of details of the stabbing and a lack of evidence of any specific psychotic phenomenology linking to the stabbing makes it difficult to determine if the mental impairment gave rise to the conduct, Prof Coyle responded: Oh really. It makes it difficult to determine. Chronic paranoid schizophrenia. By definition, a loss of contact with reality. Chronic effects of child sexual abuse and associated brain damage. Makes it difficult to determine if that is in any way related to the offending behaviour. I vehemently disagree for the reasons inherent in the arguments that I’ve expressed earlier. -- 72 of 114 -- [2025] SASC 80 Bampton J 71 310 In response to Dr Nambiar’s suggestion that he failed to entertain the possibility of a conscious motivation to not recall the stabbing, Prof Coyle said he considered this possibility and rejected it because: … she was psychotic. That simple. Again, I take note that Dr Nambiar has made these allegations against me without a scintilla of evidence to support his arguments, not a scintilla. 311 Finally, Prof Coyle was taken to Dr Furst’s comments on his report. He rejected all the criticisms Dr Furst made and did not resile from the statements in his report. In response to the suggestion that Dr Furst concluded that he could not be confident, due to lack of evidence, that Ms Rigney was mentally incompetent, as distinct from making the positive statement that she was mentally competent, Prof Coyle said, “[s]he’s either mentally competent or she’s not”. Cross-examination of Prof Coyle 312 In cross-examination, Prof Coyle said the last time he practised wholly as a clinical psychologist would have been in late 1979 to about 1982. He said his forensic work became much more significant from 1983 onwards and he has not been actively engaged in treatment of any patients for the last five years. 313 Prof Coyle said he does not have professional experience in treating schizophrenia, which he accepted was overwhelmingly done by psychiatrists. He said he has assessed numerous individuals suffering from schizophrenia and referred them on for treatment. When I asked whether he has participated in assessments as part of a team in a secure psychiatric facility, he said he did so “way back in 1976” for one year whilst he was doing a postdoctoral fellowship in mental health. He said he had not, in recent times, worked in a psychiatric facility. 314 Prof Coyle has neither given evidence nor provided reports regarding s 269C. 315 He explained he has known Prof Morris, who is a colleague and an “old school mate”, for over 60 years. He said they work out of the same offices and routinely refer work to each other. 316 Prof Coyle was asked whether the basis of his view that Ms Rigney was psychotic at the time of the stabbing was the first police interview. He agreed it was part of the assessment, along with Prof White’s opinion, the extensive medical records and history of Ms Rigney having been diagnosed with schizophrenia over a period of years, and the interaction between PTSD and schizophrenia. 317 Prof Coyle was referred to the suggestion put to him in examination-in-chief that Ms Rigney’s behaviour during the first police interview was a product of drug consumption, which he rejected, saying it was, “completely inconsistent with the psychopharmacological report of Professor White”. It was put to Prof Coyle that Prof White in fact expressed an opinion that the presentation of Ms Rigney at the time of her arrest could have been caused by a drug or drugs. Prof Coyle said he would retract his comment that the suggestion was “completely inconsistent” with -- 73 of 114 -- [2025] SASC 80 Bampton J 72 Prof White’s report, but maintained it was still inconsistent, because Prof White only said that it is possible that Ms Rigney’s presentation was due to drug use. 318 Prof Coyle was referred to his evidence that Ms Rigney was clearly not in contact with reality when she is seen staring off into the distance in the first police interview. He was asked how he could distinguish that from the presentation described by Dr Furst as her being “stoned”. Prof Coyle said he would describe Ms Rigney’s presentation as: … literally staring off into the distance, like a fixed look as if they’re seeing something. That is somewhat different from the presentation of someone who is affected by cannabis, where they would typically not be staring at a fixed point. 319 Prof Coyle was asked about his conclusion that Ms Rigney was suffering from dissociative amnesia and how this interacts with schizophrenia. He said that when a person suffering from paranoid schizophrenia engages in a frenzied attack, which is clearly traumatic, the situation can cause dissociation. He said, for reasons that are not completely understood, trauma affects the laying down of memory. He used the analogy of troops having gaps in their memory of battles and said that Prof Morris would be far better placed to address this because of his experience with Vietnam War survivors suffering from PTSD in the 1970s. He reiterated that a person with schizophrenia who suffered child sexual abuse and also has PTSD is at significant risk of autobiographical memory loss in a traumatic situation. 320 Prof Coyle agreed many victims of child sexual abuse have strong and clear memories of the abuse, saying that one of the indicia of PTSD is recurrent, intrusive and distressing memories of the abuse. He agreed that it does not follow as an inevitability that trauma in childhood begets unreliability as to memory of the events later in life. 321 Prof Coyle was asked about the Google Scholar search referred to in support of his contention that child sexual abuse causes brain damage. He said, when asked how the number of articles returned by a search reflects support for a particular scientific hypothesis, that “it is intuitively obvious that the more research articles there are on a topic, the more well-established the topic is”. Prof Coyle acknowledged that the articles returned by his Google Scholar search did not necessarily support his contention. He said that he scanned through the first 30 to 45 articles returned by his search. 322 Prof Coyle was asked about the articles he had footnoted,7 in particular, an article authored by Edwards & Ors from 2001, which was cited in support of the proposition that “child sexual abuse can impact autobiographical memory for subsequent traumatic experiences”. He agreed that the data collected in that article was part of a larger study on adverse childhood experience and the relationship to adult chronic disease and health behaviour. It was put to him that the study 7 Report of Prof Coyle dated 28 July 2022, fn 24. -- 74 of 114 -- [2025] SASC 80 Bampton J 73 concerned childhood abuse not only child sexual abuse. Prof Coyle’s response was: “[t]he methodology section speaks for itself. It is important to look at this in toto and cherry picking sections will not suffice, I’m afraid”. It was put to him that the article was not precisely on point. He disagreed and quoted from the article: The presence of elevated levels of reported amnesia in those physically – both physically and sexually abused adults prompted the examination of relationship between reported amnesia and depression. 323 Prof Coyle expressed the view that the first police interview, coupled with the evidence of Ms Rigney’s longstanding history of schizophrenia, PTSD, and child sexual abuse, are the most important pieces of evidence. Prof Coyle said he did not make much of the CCTV footage of Ms Rigney walking along Goodman Avenue and that he could not even determine whether it was Ms Rigney who was captured in the footage. He said he did not regard the footage as having value from a psychological perspective, explicitly rejecting the suggestion that the footage showed that Ms Rigney could control what she was doing. 324 Prof Coyle agreed that the second police interview might reflect Ms Rigney trying to make sense of what happened the day of the stabbing. However, he said that he would very much doubt it because of the conjoint operation of the various factors he mentioned regarding dissociative amnesia. He agreed that Ms Rigney describing being at Maria Luis’ home, giving examples of what she was wearing, and acknowledging the death of Maria Luis occurred by stabbing, could reflect memories, but also could be something she invented to make sense of something, or it could be attributed to information she had obtained post-event. Prof Coyle said it is incredibly difficult in a case like this to form conclusions about these matters. He emphasised that dissociative amnesia does not necessarily result in a complete loss of memory regarding the events, and that “little snippets [can] sneak through”. 325 Prof Coyle was asked whether it was possible that Ms Rigney deliberately avoided speaking about the stabbing when he interviewed her. He said it is possible, but that he did not detect any evidence of her engaging in deceitful conduct. 326 When it was put to Prof Coyle that there was some parts of the second police interview where Ms Rigney distances herself from involvement in the stabbing, and he was asked whether that would bespeak a lack of psychosis at the time, Prof Coyle said: In my view, as I said unequivocally yesterday, and I shall not resile from it, she was psychotic at the time of the crime and she was psychotic afterwards. She is still psychotic. … He agreed schizophrenia is a disease that can wax and wane but said it does not resolve the underlying psychosis, and that anything reported by the patient that is -- 75 of 114 -- [2025] SASC 80 Bampton J 74 sought to be relied upon must be regarded with extreme suspicion. Having accepted that the condition can wax and wane, Prof Coyle was asked how he could say she was psychotic at the time of the stabbing. He said: Because it’s waxing and waning within the context of psychosis. Someone who has a delusional system who sees things and smells things and hears things, it doesn’t happen to the same extent every day but it’s still there, they’re still psychotic. They’re still psychotic which, by definition, means a loss of contact with reality. There’s no getting around that. 327 Prof Coyle was asked to identify evidence suggesting that Ms Rigney did not know her conduct was wrong. He said the prosecution evidence indicates that she was suffering from paranoid schizophrenia at the time, and that Dr Nambiar and Dr Ferris initially said that she satisfied the s 269C criteria. The prosecutor clarified that she was not asking him to look at the opinions of the other psychiatrists, but to the evidence in the brief, including the evidence of her behaviour and what occurred on the day. Prof Coyle said he did not think the police brief could be interpreted without reference to the psychiatric and psychological opinions, and that her behaviour on the day of the stabbing was not seen. He said: We make inferences from the number of stab wounds, the time over which they were inflicted upon the deceased. We make inferences as to her behaviour based on her longstanding history of schizophrenia, her longstanding comorbid post-traumatic stress disorder, the undoubted interaction between those two conditions to induce dissociative amnesia. We make inferences from her failure to be able to recall things and we make inferences from her behaviour when she was interviewed on the second occasion. But no-one saw the killing. So, by definition, the assessment of whether or not she met a mental standard for incompetence must rely upon the psychiatric and psychological evidence and I can answer it in no better way. I can’t add anything, nor will I subtract anything from that answer. 328 Prof Coyle was asked about the CCTV depicting Ms Rigney departing from the scene of the stabbing with what appeared to be a degree of speed. Prof Coyle said that this could be attributed to any number of phenomena, such as a direct reflection of her psychotic state. He said it cannot be inferred from such movement that Ms Rigney knew that her conduct was wrong. Prof Coyle was also asked about the significance of Ms Rigney possibly secreting a weapon. He again said that this does not indicate she knew the wrongfulness of her conduct or that she could control it. He said there could be a number of other explanations, suggesting “[t]he devil might have been ready to appear in front of her and she was going to stab him. We don’t know because she was, by definition, psychotic”. 329 Prof Coyle was asked to assume there was animosity between Maria Luis and Ms Rigney and whether that had any significance in terms of competency. Prof Coyle said it would explain only some elements of the behaviour, but it would not, in any event, overcome the underlying issue of psychosis. He said it might provide a partial explanation for the frenzied attack, but that it still needed to be considered in the context of Ms Rigney being grossly psychotic. He rejected the suggestion that this would erode the opinion that Ms Rigney was completely -- 76 of 114 -- [2025] SASC 80 Bampton J 75 unable to control her conduct, saying that it might simply provide an explanation as to why she stabbed the deceased. 330 Noting that he had expressed his opinion in terms of Ms Rigney satisfying ss 269C(1)(b) and/or (c), Prof Coyle was asked how those two aspects of the test worked together. He said: Because it’s entirely possible that both of those things happened at the same time. It’s entirely possible that she didn’t know it was wrong and she was unable to control her conduct. When someone is delusional and they have, for example, command voices … then there are two issues that can be conjoined … 331 Prof Coyle said the information in this particular case did not permit him to say whether it was either or both of ss 269C(1)(b) and (c) that were satisfied. Prof Coyle agreed he did not have any evidence that, at the time of the stabbing, Ms Rigney was experiencing command hallucinations. He said it was possible, but “we don’t know”. 332 Prof Coyle was asked whether the evidence of Ms Rigney attending at Service SA and Cash Converters, where she undertook a series of transactions a number of hours before the stabbing, showed that she was able to control her conduct at that time. He agreed she was certainly able to control that conduct, but said that this does not have any particular bearing on what happened thereafter. Prof Coyle said a person experiencing psychosis can have moments or hours of lucidity such that you cannot, by reference to one event in the course of the day, determine their competence later. He reiterated that the CCTV footage, the fact that Ms Rigney knew Maria Luis sold cannabis, and the fact that Ms Rigney may have burned a clothing item do not demonstrate anything of value from a psychological perspective. 333 I asked Prof Coyle whether it was a reasonable inference that, having gone to Service SA to get confirmation of her identity in order to borrow money from Cash Converters, when Ms Rigney was walking up to the house of a woman she knew sold cannabis, Ms Rigney’s state of mind was an intention to buy drugs. Prof Coyle agreed that was a reasonable inference to draw but said it does not help in determining what happened thereafter. He disagreed that Ms Rigney attending the house with that intention indicates she was able to control her conduct, saying that the smallest thing can cause someone to completely decompensate: “[f]or no particular reason, they will just … lose it”. He said this phenomenon is seen all the time in psychiatric facilities, even when people are fully medicated. 334 It was put to Prof Coyle that he had been critical of Dr Nambiar’s second report. Prof Coyle replied that Dr Nambiar had been fairly critical of him. With respect to Prof Coyle’s suggestion that Dr Nambiar was affected by forensic bias, it was put to Prof Coyle that Dr Nambiar, as an expert, can make assumptions without becoming biased. Prof Coyle maintained that the way in which the DPP letter was written, the timing of it, and the change of Dr Nambiar’s opinion thereafter, raised the issue of unconscious bias. -- 77 of 114 -- [2025] SASC 80 Bampton J 76 Re-examination of Prof Coyle 335 In re-examination, Prof Coyle was asked about the articles he had retrieved from Google Scholar that he said demonstrated the link between child sexual abuse and brain damage. Four of these articles were tendered as exhibit D20. 336 None of these articles meaningfully assist in determining this matter. The existence of four articles, leaving aside the question of whether the support Prof Coyle’s assertions, does not allow me to make a finding about whether child sexual abuse causes brain damage. In any event, there is no evidence of any brain damage suffered by Ms Rigney. Prof Morris 337 Prof Morris is a psychiatrist practising in Queensland who became a fellow of the Royal Australian and New Zealand College of Psychiatrists in 1985. Prof Morris has been in private practice on the Gold Coast since about 2004 and prior to that, was the Director of Mental Health for the Gold Coast. He gave evidence he specialises in medico-legal assessments, psychiatry in older patients, and addiction medicine, and that he has been the visiting Professor of Psychiatry at Bond University since 2009. He is the President of the Australian and New Zealand Mental Health Association, an organisation he established in 2000, and is the President of the National Association of Practising Psychiatrists. He was made a Member of the Order of Australia in 2020. 338 Prof Morris said that he has given expert psychiatric evidence in various jurisdictions. He said he has given evidence on the issue of mental competence before the Queensland Mental Health Court probably about five times. Prof Morris’ reports dated 22 August 2022 and 28 August 2022 339 Prof Morris prepared his report dated 22 August 2022 following two one-hour examinations of Ms Rigney by video conference. He concluded Ms Rigney was suffering a serious mental illness at the time of the stabbing; namely, a clinically escalating and severe treatment-resistant schizophrenia, as well as chronic PTSD secondary to developmental trauma and child sexual abuse. He also considered that she had borderline personality traits. He was of the view that at the time of the stabbing, these conditions would have rendered Ms Rigney psychotic, thought disordered, impulsive, irrational, and unable to control her behaviour. He concluded that as a consequence of her mental impairment, it was more likely than not that she did not know her conduct was wrong and/or was totally unable to control her conduct. 340 Ms Rigney’s solicitors also sought Prof Morris’ opinion as to whether her memory difficulties could be clinically explained or alternatively, whether he agreed with the proposition that she was able to provide a truthful account. Prof Morris said in individuals suffering severe psychopathology like schizophrenia and PTSD, heightened stress and arousal can result in amnesia for part, or the whole, of a traumatic incident. He reported that, while it is possible -- 78 of 114 -- [2025] SASC 80 Bampton J 77 that Ms Rigney is capable of recounting the events surrounding the stabbing, it is more likely that she experienced this amnesia. 341 In his supplementary report dated 28 August 2022, Prof Morris detailed the history he obtained from Ms Rigney during his two examinations. He said she was repeatedly sexually abused as a child and now suffers symptoms of PTSD from the trauma, including intrusions, avoidance, emotional liability, hyperarousal, and difficulty controlling intense emotions, especially when threatened. Prof Morris also described Ms Rigney as having schizophrenia characterised by paranoid delusions of ghosts, aliens, and the devil influencing her, suspicious fears of others, auditory and visual hallucinations, and difficulties with attention, concentration, and thinking clearly. He noted she has a history of illicit drug use including cannabis from when she was an adolescent, use of which she continued up to the time of the stabbing, usually on a daily basis, along with methamphetamine less regularly. Prof Morris reported that Ms Rigney’s description of the events surrounding the stabbing was limited. She told him she remembers walking towards Maria Luis’ house in the afternoon and placing her backpack in the front garden of a neighbouring property. She reported her next memory was seeing police officers enter her home with guns pointed at her. She told Prof Morris she had no memory of the stabbing and denied wishing to harm the victim. Prof Morris reported that “she mentioned [Maria Luis] might be an alien, possibly controlling [her], but was unclear about this”. 342 Prof Morris said Ms Rigney tried to be helpful during his interviews in providing a history and responding to questions, at times lucidly, but at other times, her answers were difficult to understand. He said she was reluctant to discuss the sexual and childhood abuse in detail, but that she provided a history of psychotic experiences of delusions, hallucinations, and suspiciousness. He reported that he considered medical records related to the frequent episodes of care for her mental illnesses during her pregnancy and following the birth of her son. These records reflected Ms Rigney’s history of severe treatment-resistant schizophrenia with delusions, hallucinations and thought disorder, developmental trauma associated complex PTSD, personality (cluster B) problems, and impulsive, angry, and aggressive behaviour, all exacerbated by illicit substance use and complicated by treatment compliance problems. He noted that just prior to the stabbing, community mental health staff tried to assess Ms Rigney but she refused contact, with the result that she did not receive her depot antipsychotic medication within the recommended time. He also referred to civilian witness statements describing Ms Rigney behaving in an increasingly disturbed and aggressive manner in the lead-up to the stabbing. 343 Prof Morris reported that Ms Rigney’s behaviour during the first police interview suggests she was psychotic at the time and possibly under the influence of cannabis or experiencing the withdrawal effects of methamphetamine. He noted in particular that she was very sedated, had difficulty concentrating, appeared perplexed and vague, was staring into the distance, and claimed she was pregnant. He said her behaviour during the second police interview, which included -- 79 of 114 -- [2025] SASC 80 Bampton J 78 irritability, incongruent facial expressions, appearing distracted, and making unusual statements, also suggests she was psychotic at that time, although she was more alert and coherent. 344 Prof Morris reported that the documentation he reviewed led him to conclude that Ms Rigney was severely psychiatrically unwell at the time of the stabbing. He said the effect of her conditions, which was escalating, would be to impair her rational thinking, heighten any paranoid fears and delusions, limit her capacity to discriminate hallucinations from reality, inhibit her control over her anger, affect her ability to recall clearly what happened in a high arousal and emotional incident, and impair her capacity to conform her behaviour to accepted norms. He further stated the pattern of stabbing injuries suggests an uncontrolled, frenzied attack. 345 He concluded that the severity of Ms Rigney’s impairments at the time of the stabbing would have significantly affected her ability to know her conduct was wrong and/or rendered her totally unable to control her conduct. He therefore considered Ms Rigney had the mental incompetence defence available to her. Finally, Prof Morris referred to Dr Nambiar and Dr Ferris changing their opinions after considering the DPP letter and said that after reading the letter himself, he maintained his view. Dr Ferris’ report dated 29 August 2022 responding to Prof Morris’ report 346 Dr Ferris stated that after having thoroughly considered Prof Morris’ report, her opinion remained unchanged. Prof Morris’ evidence 347 Prof Morris was asked in evidence-in-chief, in the context of explaining various psychiatric concepts relevant to schizophrenia, whether psychosis and schizophrenia would be obvious to a layperson. Prof Morris said the answer is “yes and no”, explaining that if the person is floridly out of control, running around naked, or being threatening to others, then the general public would consider the person to be really unwell. He went on to also explain that many patients treated with drugs and psychological treatments can experience periods of being fairly quiet as far as their illness is concerned. He said that while there is no cure for schizophrenia, a patient’s condition can fluctuate and when their symptoms are low, the public may not see that they have a particularly problematic illness. 348 Prof Morris gave evidence explaining the antipsychotics used to treat schizophrenia, before turning to outline PTSD. He said PTSD and schizophrenia can occur together as comorbid conditions. He said, in his experience, a person with PTSD who then develops schizophrenia is going to have much less control over their behaviour because: … PTSD, which brings into effect the anxiety, the suspiciousness, the hyper-arousal, the sense that anybody else is a threat, the vigilance that they have, all those elements, when you put schizophrenia on top of that, which is delusions and often paranoid delusions, -- 80 of 114 -- [2025] SASC 80 Bampton J 79 difficulties with understanding what’s going on around you, hearing voices, seeing visions of things, you add them together and it’s a pretty toxic mix. He further said, in his experience, if a person has PTSD and schizophrenia, the PTSD is likely to make the schizophrenia much more florid and exaggerate the symptoms. 349 Prof Morris described that Ms Rigney reported problems with ghosts, hearing voices, and psychotic phenomena. She also reported one of her major problems being that “whenever she gets threatened or frustrated or whatever, she arcs up, gets very angry very quickly which, of course, is a symptom – can be a symptom of PTSD”. 350 Prof Morris said that Ms Rigney’s childhood involved trauma. Ms Rigney told him the trauma included sexual abuse, but she did not want to talk about it, and it was detailed in a document that she handed him. 351 Prof Morris was taken to his report dated 22 August 2022 under the heading “Mental competence”. Prof Morris confirmed that he formed the opinion that Ms Rigney had a mental impairment which was a very severe, treatment-resistant, chronic schizophrenia, complex PTSD, and borderline personality traits. In relation to s 269C(1)(a), Prof Morris said: Well, that was tough because it’s a bit hard to know. You know, I’m not a fly on the wall. It’s very hard – the accused was not able to give me an account of what happened. She says she can’t remember what happened. So there wasn’t enough information there for me to really say that I was convinced that she didn’t know the nature and quality of the conduct. I mean, she went – I looked at the CCTV stuff. She went along – this is on the second time that she was on the – in the video. The first time I think was at 3.30 one afternoon – the afternoon of the attack. The second time was about 4.51, I think, and on that occasion she sort of was walking towards the house, she dropped off a backpack and put it over someone’s fence, and then the video doesn’t show much more apart from her going up to the house, the dog comes out for a few minutes and looks around, goes back towards the house, and then she is seen coming out of the house. So it seems like she was aware of what was going on at the time, or whatever. So I thought that she probably didn’t have a defence on that particular arm. In relation to s 269C(1)(b), Prof Morris said: … again, I’m not a fly on the wall there. It’s very hard. All these cases are very difficult to be able to entirely be sure, but as much as I could be in terms of the likelihood of the situation, the fact that she had severe schizophrenia and in the lead-up during that year, she was showing signs of being very poorly controlled and she has PTSD and she has the borderline personality problems … Prof Morris said he considered that Ms Rigney would not have been able to reason about whether her conduct was wrong as perceived by reasonable people “based on the fact that she was so profoundly unwell”. 352 In relation to s 269C(1)(c), Prof Morris said that, in his opinion, Ms Rigney was unable to control her conduct because of the effect of her conditions. He also -- 81 of 114 -- [2025] SASC 80 Bampton J 80 said that the frenzied nature of the stabbing “would be consistent in [his] mind with a person that was really not controlling themselves”. 353 Prof Morris was asked whether his opinion that Ms Rigney suffered from PTSD was supported by entries in the medical records. Prof Morris referred to entries dated 2017 recording diagnoses of Ms Rigney’s, including drug-induced psychosis, developmental trauma, complex PTSD, and borderline personality traits, also noting the overlay of cannabis and methamphetamine use. He was also taken to exhibit D18, tab 16, and referred to an entry that reads: We suggest [Ms Rigney’s] significant developmental trauma has led to complex PTSD and personality vulnerabilities where she tends to decompensate, experience dissociation or her experience [flashbacks] at times of distress. Prof Morris referred to Ms Rigney’s numerous hospital admissions and the occasions she was diagnosed with drug-induced psychoses. He said he did not agree with that diagnosis having regard to the history as a whole, including the symptoms she was presenting with. He said that, in his opinion, she had a severe, chronic schizophrenia that was treatment-resistant in the sense that she has needed quite significant inputs from various drugs to try and control it. Prof Morris said he considered that she had been in partial remission at times, and he explained that: … if a person becomes in partial remission, in other words they are not completely well but they are well enough to be able to interact with their environment and do other things, they still might have delusions and hallucinations … so they are not well, they are not resolved. They are partially in remission. Well enough to be coping. But they are not fully recovered. And in those cases you would say well they are probably treatment resistant because they are still showing signs of the illness despite maximum treatment. 354 Prof Morris was asked, assuming that Maria Luis did not like selling drugs to Aboriginal or young people, whether if Ms Rigney had sought to purchase cannabis from her and had been rebuffed, Ms Rigney could have become fixated on Maria Luis by reason of her schizophrenia. Prof Morris agreed this was possible and said that: … if a person, through their delusional systems, has got a predisposition to seeing anybody who might be not helpful to them, antagonistic towards them, threatening or frustrating, then that person can become part of an irrational belief that that individual is acting against their best interests. The step to that is the threshold is reduced massively because they’ve got the psychosis. So that could be one of the explanations. 355 Prof Morris referred to collateral evidence from witnesses of Ms Rigney’s behaviour prior to 7 December 2018, such as where she appeared to run after a car calling out to women inside, who were associates of Maria Luis, and acting aggressively, and another occasion where she was observed walking topless down the street, holding a knife, and indiscriminately threatening people. Prof Morris speculated that the former incident might suggest that Ms Rigney thought Maria Luis and anyone connected to her was against her, or it could suggest, together with the latter incident, that she was losing her capacity to control her behaviour, acting aggressively and strangely towards other people generally. -- 82 of 114 -- [2025] SASC 80 Bampton J 81 Prof Morris noted that in the year before the stabbing, there was an escalation in Ms Rigney’s condition and that she was also starting to use methamphetamine again, along with cannabis. 356 Prof Morris said that if Ms Rigney had been rebuffed on the first occasion she went to Maria Luis’ home and again when she returned on the second occasion, that would have been “an additional reason for her to blow up, and start to behave in a way that was consistent with the severe psychosis and the PTSD condition that she had”. He agreed if this had occurred, it would be consistent with his conclusion that Ms Rigney was mentally incompetent at the time of the stabbing. He explained that when PTSD is superimposed on schizophrenia, it reduces the person’s ability to control behaviour in response to frustration, threat, altercation, or argument. He said the person’s impulses are not under control such that when they start acting, they cannot stop. 357 Prof Morris said Ms Rigney’s conduct in going to Cash Converters and Service SA before the stabbing, and possibly disposing of evidence after leaving Maria Luis’ house, is not inconsistent with her being psychotic. He said: … patients who have psychosis can do basic tasks … Patients can do these things. It’s the context of the circumstances within the environment that she was in with the victim. The fact that they can go and put a bag somewhere, wherever else, makes no difference to the fact that they suffer from a psychotic condition. 358 Prof Morris reiterated that he considered Ms Rigney was psychotic during the first police interview, but that she looked sedated and was possibly under the influence of cannabis or coming off methamphetamine. He also formed the view she was psychotic in the second police interview, even though her demeanour was more responsive, coherent, and lucid than during the first police interview. He said it was strange that in the second police interview, Ms Rigney said she visited a woman for cannabis earlier in the day at 12:05 pm even though she had not been at Maria Luis’ home at that time. Prof Morris also said Ms Rigney smiled incongruently and seemed preoccupied at stages of the second police interview. He said her comments were incoherent, disjointed and disorganised and that her behaviour was very unusual, incoherent, inappropriate, and incongruent. 359 Prof Morris was asked whether the contrast between Ms Rigney’s presentation in the first and second police interviews is reflected in the medical notes. Prof Morris said that there seemed to be a pattern of Ms Rigney being floridly unwell and then improving with, he assumed, some degree of support and control. 360 Prof Morris was asked whether there was a psychiatric explanation for Ms Rigney’s assertion that a black man was responsible for the stabbing. Prof Morris said it was possible that Ms Rigney was deluded or that she was looking for an explanation. He said it was possible that she made it up to deflect guilt, but it was also possible that it was part of her delusional system in the sense that she believed someone else must have been responsible for the stabbing. He -- 83 of 114 -- [2025] SASC 80 Bampton J 82 was asked whether if Ms Rigney were attempting to deflect guilt, she would still have been psychotic. Prof Morris said that people can try to deflect guilt whether they are psychotic or not. 361 Prof Morris also said that PTSD, on its own or even more so in conjunction with schizophrenia, can have an impact on memory. He said amnesia is less likely to occur in people with schizophrenia alone unless they are extremely excited such that they cannot put down memories. He said, in his opinion, the conjoined operation of PTSD and schizophrenia explains Ms Rigney’s partial memory of the events around the time of the stabbing. Cross-examination of Prof Morris 362 Prof Morris was asked in cross-examination whether one of the principal areas of his practice was medico-legal assessment. He agreed this is one area he has had experience with. He was asked whether, at the time he was giving evidence, it was his principal area of focus. His answer was: I would say it’s a part of my area of focus but not principal. The principal area of my focus these days is looking after and assessing older individuals who come forward who have got memory problems and are worried about getting dementia and things of that nature. 363 Prof Morris said forensic work would account for about 20 to 30 percent of his work. 364 The prosecutor pointed out that Prof Morris framed his conclusion in terms of s 269C(1)(b) being satisfied and/or s 269C(1)(c), and asked him to explain the meaning of the and/or formulation. Prof Morris replied: A. I think it reflects my naivety counsel. I was basically convinced that she had both the elements but I just didn’t know how to – if one wasn’t accepted then the other one needed to come into play, so I guess it’s a level of inadequacy on my behalf to not make it sort of clearer, I’m sorry. Q. You weren’t sure that the test was made out on either of those limbs. A. Well, I was sure that the test was made out on both but I just didn’t quite know what – whether I should have put ‘and/or’ or whatever. I think it’s a reflection of my being not quite sure how to phrase it. Not that I wasn’t sure that she had both limbs that could be sustained. 365 He was asked whether he borrowed the wording from Prof Coyle. He denied this and said that it was his own wording. The prosecutor then asked him if he worked in the same suite of offices as Prof Coyle, to which he replied: No. I think he might come into the offices at weekends and stuff but I wouldn’t call myself in an office that I work with him because I don’t see him at all. He I think sees most of the people that he sees – visits them or goes to gaols or maybe does video stuff, but that is an office that’s operated by the psychologists and I rent my room off them. Whatever they do with people at weekends and stuff for incidental things is up to them but I wouldn’t say I was working with him definitely not. -- 84 of 114 -- [2025] SASC 80 Bampton J 83 I then asked him whether he and Prof Coyle physically have the same suite of rooms, to which he replied, “[t]here is four – there is five rooms in this particular suite of offices”. The prosecutor asked him whether he had discussed this matter with Prof Coyle. Prof Morris said he only spoke to Prof Coyle to ask him for a copy of the DPP letter, and he denied that any discussion about the letter occurred. 366 Prof Morris was asked whether the conclusions in his first report were influenced by Prof Coyle’s report. He said that he read all the reports and considered their arguments. It was again put to him that Prof Coyle’s conclusion is in the same terms as his conclusion, including the “and/or” formulation. It was then suggested to him that the particular wording of his conclusion had been taken from Prof Coyle’s conclusion. Prof Morris denied this, saying his report was prepared “separately and independently”. 367 It was put to Prof Morris that the footage from the CCTV cameras demonstrated Ms Rigney was able to control her conduct up to the point she arrived at the Luis house. Prof Morris argued that she could control the walking, but said that there are different levels of conduct. It was put to him there was no evidence to suggest that she was totally unable to control her conduct within the Luis home. Prof Morris said he would not agree with that proposition. The prosecutor then put to Prof Morris that he did not have any evidence of what happened inside the house, to which he said: … I’m not a fly on the wall, I have to interpret what I’ve seen and the medical history, examination of the patient and the witness statements to identify that she had - she was very unwell. She had psychosis, she had PTSD, she had impulse control problems, she had a history of arcing up and becoming very violent in other situations, but no, I wasn’t there at the time of the actual offence; but there was no other evidence that I could see that says someone else was there at the time of the offence. So there’s a lot of difference between walking up a street and being in a situation where you may have been thwarted, denigrated, refused to be given drugs, told that you were a person from another culture and another race and they don’t like you. I mean I don’t know what happened there, but I do know that in her state of mind, with all those conditions, that if she was confronted with that she would have ended up in a situation where she didn’t know what she was doing was wrong and she couldn’t control what she was doing. That’s very different to being able to walk up the street by herself. 368 Prof Morris agreed that a person with schizophrenia may not consistently present in a state of florid psychosis. It was put to him that there was no evidence that Ms Rigney was suffering from florid psychosis at the time she went into Maria Luis’ house. Prof Morris said: No, we don’t know, so, we do know that she was floridly psychotic in the lead-up to that year and we do know that she exhibited psychosis in the interviews afterwards and that subsequently since she’s been incarcerated she’s been very unwell with a psychotic illness. 369 It was put to Prof Morris that at the time Ms Rigney was at Cash Converters and Service SA to obtain identification and a loan, she was not presenting as floridly psychotic. Prof Morris disagreed, saying that patients who are florid and quite unwell are still able to do basic tasks. He was also asked about whether, if -- 85 of 114 -- [2025] SASC 80 Bampton J 84 Ms Rigney had left Maria Luis’ house quickly and concealed a weapon, it would suggest that she knew her conduct was wrong. He said it is possible but that this conduct is not necessarily inconsistent with psychosis, and it does not overwhelm the other evidence. 370 Prof Morris agreed that there was no evidence of Ms Rigney experiencing command hallucinations at the time of the stabbing. He said that most people with schizophrenia lack insight into their condition and believe their hallucinations are true, but agreed that command hallucinations are not necessarily irresistible. 371 Prof Morris was asked about an email he sent to Ms Rigney’s solicitor in which he referred to Ms Rigney apparently aggressively targeting Maria Luis on a number of occasions as well as others, some of whom may have been viewed by Ms Rigney as associated with Maria Luis. He said he was trying to identify a pattern of behaviour that manifests when Ms Rigney is unwell. He was asked to explain the significance of Ms Rigney targeting Maria Luis’ associates. Prof Morris said this could be the result of Ms Rigney having some form of paranoid delusion about Maria Luis and her associates or due to her simply not liking Maria Luis. He said he could not state which potential explanation was more likely. He agreed that if Ms Rigney were targeting the deceased aggressively, that might reflect some motive for the attack, but said that this does not necessarily mean that she was not under psychotic influences at the time of the stabbing. He agreed that there was no evidence of Ms Rigney holding a delusional belief system about Maria Luis that caused Ms Rigney to target her. Prof Morris rejected the suggestion that he had not referred to Ms Rigney attacking or being aggressive towards Maria Luis and her associates in his reports because it did not sit comfortably with his conclusion that Ms Rigney was mentally incompetent. 372 Prof Morris was asked to explain the basis of his conclusion that Ms Rigney was completely unable to control her conduct at the time of the stabbing, as distinct from having some capacity. He said he relied on her suffering from the combination of PTSD and treatment-resistant schizophrenia, and the severity of those conditions, which would lead to a situation where a person cannot control their behaviour. He said he also relied on the frenzied nature of the stabbing. While he agreed that a person concealing a weapon or otherwise distancing themselves from the scene of a crime might demonstrate capacity to control conduct, he said it did not overturn his opinion in this case having regard to the severity of Ms Rigney’s illness. 373 Prof Morris was asked, assuming that Ms Rigney was under a therapeutic level of aripiprazole at the time of the stabbing, whether that would have some capacity to diminish her symptoms of delusions and hallucinations. He said it does have some capacity but, in Ms Rigney’s case, the medication did not appear to have been effective having regard to the escalating nature of her illness over the year leading up to the stabbing. -- 86 of 114 -- [2025] SASC 80 Bampton J 85 374 Prof Morris was then asked about his conclusions regarding Ms Rigney’s PTSD symptoms, including getting angry in response to threats or frustration. Prof Morris was asked whether these behavioural responses were also due to a personality disorder. He agreed and said in Ms Rigney’s case, it seems that her schizophrenia, PTSD, and borderline personality traits can all affect her ability to respond. 375 Prof Morris described borderline personality traits as “difficulty dealing with frustration, threats, [and] relationships” as well as becoming “excessively dependent” and then “excessively rejecting”. He said that people with such traits react to circumstances in quite impulsive and often exaggerated ways. 376 Prof Morris agreed that Ms Rigney presented as intoxicated in the first police interview and that it was likely she was intoxicated by cannabis, although it could have been some other drug. He agreed that her presentation changed in the second police interview, and that the change in her presentation could possibly reflect a dissipation of intoxicants. 377 Prof Morris was asked about the reference in his report to Ms Rigney telling him that Maria Luis “might be an alien, possibly controlling [her]”, although she was “unclear about this”. Prof Morris gave evidence he did not know what question he had asked that elicited this comment. He explained he was asking broad questions of Ms Rigney about whether she suffered from any thoughts about people influencing her or controlling her, as delusions of influence are a common feature of schizophrenia. He said he attempted to explore this comment with Ms Rigney because he wondered whether it was psychotic phenomena, but that he could not get any further and “she didn’t seem to explain any more”. Prof Morris explained the words “but [she] was unclear about this” were meant to convey his assessment that it was unclear what Ms Rigney meant by the comment and that he was unable to get further specific information about it. Prof Morris’ evidence on this subject does not detail whether Ms Rigney was telling him that she considered Maria Luis might be an alien at the time of the stabbing or at some other time. Re-examination of Prof Morris 378 In re-examination, Prof Morris was asked about his agreement in cross-examination with the proposition that there was no evidence that Ms Rigney suffered from command hallucinations. He clarified that he could not remember her saying that at the time of the stabbing, she had a command hallucination to kill or harm the victim. Defence submissions 379 The defence submitted that the opinions of Prof Coyle and Prof Morris should be accepted in preference to those of Dr Nambiar, Dr Ferris, and Dr Furst. It was pointed out that four of the five experts have at some point considered that Ms Rigney was mentally incompetent at the time of the stabbing. The defence -- 87 of 114 -- [2025] SASC 80 Bampton J 86 invited the Court to prefer the earlier opinions of Dr Nambiar and Dr Ferris unless satisfied of the cogency of their reasons for revising their opinions. Diagnosis of mental impairment 380 The defence noted that all the experts agree that at the time of the stabbing, Ms Rigney suffered from a mental impairment within the meaning of s 269A; namely, chronic treatment-resistant schizophrenia. The defence suggested that nothing appears to turn on whether Ms Rigney’s schizophrenia is properly classified as being the disorganised or paranoid type, noting Dr Nambiar’s evidence that severe thought disorder can impair a person’s ability to reason to the point of being mentally incompetent. 381 While acknowledging that it is not necessary for the Court to make such a finding, the defence nonetheless invited the Court to accept that Ms Rigney was also suffering from PTSD, which the defence says would have exacerbated her schizophrenia and is likely to have adversely impacted her memory of the stabbing. The defence submitted that the evidence of Prof Coyle and Prof Morris should be accepted because they considered PTSD in the context of interviewing Ms Rigney for the purpose of preparing reports, whereas Dr Nambiar, Dr Ferris, and Dr Furst did not. The defence also pointed out that Prof Coyle administered the PCL-5 to Ms Rigney, that Prof Morris has a research and clinical interest in PTSD, and that the evidence of neither expert on this topic was challenged in cross-examination. 382 It was submitted that while Dr Nambiar disputed the diagnosis of PTSD, he did not dispute the diagnoses of “complex PTSD” set out in Ms Rigney’s medical records. However, I note that Dr Nambiar’s evidence was that “complex PTSD” is “another way of formulating [BPD]” and is therefore distinct from PTSD. The defence was also critical of the fact that Dr Nambiar’s opinion on this topic was expressed for the first time in cross-examination. Purposeful conduct 383 The defence stated it is not clear what the prosecution seeks to make of the evidence concerning Ms Rigney placing a backpack on the front lawn of a neighbouring property prior to attending the Luis premises on the second occasion, noting that it was not raised in cross-examination of Prof Coyle or Prof Morris. The defence submitted that the bag contained items which would have served no purpose in Ms Rigney attending Maria Luis’ house, which the defence suggests might indicate a disorganised state of mind. 384 In response to the suggestion that Ms Rigney was in contact with reality immediately after the stabbing because she returned home, the defence pointed out that the evidence only establishes that Ms Rigney departed in the general direction of her house and was found there by police later that night. -- 88 of 114 -- [2025] SASC 80 Bampton J 87 385 The defence challenged the prosecution suggestion that Ms Rigney must have secreted a knife used in the stabbing when she left the premises, noting that it is unknown whether a knife was placed in the bag. 386 The defence referred to the statement of forensic scientist Michael Cook dated 12 July 2019, in which he said that while the pattern on the burnt cloth found in Ms Rigney’s backyard is not obviously different from the clothing worn by her in the CCTV footage, he could not comment on whether they were similar. The defence submitted that in these circumstances, the prosecution submission that Ms Rigney had burned clothing to dispose of incriminating evidence should be rejected. 387 The defence contended it is significant that in Dr Ferris and Dr Nambiar’s initial reports, they considered that Ms Rigney’s actions prior to and after the stabbing were not inconsistent with her being mentally incompetent to commit the offence. The defence noted that these opinions remained unchanged at trial. 388 I indicate I have not taken into account the evidence regarding the backpack, the burnt clothing, or the prosecution’s suggestions that Ms Rigney left Maria Luis’ house with a degree of speed and deliberately secreted a knife. Motivation for the stabbing 389 The defence referred to Dr Ferris’ report dated 26 July 2021, which records that Ms Rigney was at that time still experiencing command hallucinations and responding to perceptual disturbances, although she could resist the commands by using “distraction techniques” and “assistance from nursing staff”. The defence submitted it can be inferred that without the benefit of “carefully managed pharmacological treatment, behavioural strategies, and the presence of trained mental health nursing staff, she may not have been able to control her behaviour in response to these commands”.8 In this regard, I note there is no evidence identified by the experts in this matter that Ms Rigney experienced hallucinations commanding her to harm others. 390 In response to Dr Furst’s evidence that he could not comment on whether the nature of the attack suggested a psychotic or non-psychotic motive in the absence of evidence as to what precipitated the stabbing, the defence notes the lack of direct evidence but says that it is: … legitimate to infer from the gross, frenzied and impulsive nature of violence perpetrated against a victim by a person with entrenched paranoid schizophrenia that the more likely explanation for the violence is that it was the product of psychosis. (Emphasis in original) 8 Defence written submissions at [120]. -- 89 of 114 -- [2025] SASC 80 Bampton J 88 The defence submitted this approach is consistent with that taken by Prof Coyle and Prof Morris, as well as Dr Nambiar and Dr Ferris in their earlier reports. 391 The defence also characterised the frenzied attack as “extraordinary” having regard to the small bag of cannabis stuck to Ms Rigney’s leg at the time she was located in her home by police, which the defence says must have been obtained by Ms Rigney from a source other than Maria Luis either before or after the stabbing.9 The defence submitted that in circumstances where Ms Rigney already had cannabis or could obtain it from a source other than Maria Luis, there was no need for her to obtain it from Maria Luis and therefore no need to have attacked her. I disagree. I infer from the account given by Ms Rigney during the second police interview, as well as collateral information, that the bag attached to her leg was obtained from Maris Luis on 7 December 2018. Ms Rigney told police during the second police interview that she went to the dealer’s house, where she purchased a $50 bag. In response to a question as to whether she had purchased cannabis from Maria Luis, she replied “the bag you brang it in when we got arrested last night”. When police remarked that there was only a tiny bit in the bag, she said “I smoked it I was straight up stoner bro that’s all I do is smoke weed…”. The defence said that even had Maria Luis refused to supply Ms Rigney with cannabis, the nature of the stabbing is “grossly disproportionate to her having failed to obtain a small amount of cannabis for smoking”. The defence submitted that these matters tend to indicate that Ms Rigney was seriously mentally impaired at the time of the stabbing. 392 The defence accepted that Ms Rigney’s drowsy or sedated appearance during the first police interview could be attributed to drugs but said that it would be speculative to go beyond that, given the toxicology report. The defence submitted that the whole of the evidence indicates that Ms Rigney was psychotic at the time of the first police interview. Ms Rigney’s lack of memory of the stabbing 393 The defence submitted that the evidence of Prof Coyle and Prof Morris, supported by the other experts, establishes that there are medical or psychiatric explanations for Ms Rigney’s claimed memory loss surrounding the stabbing. The defence said that in these circumstances, it cannot be more likely than not that Ms Rigney was feigning memory loss. Absence of self-report from Ms Rigney regarding symptoms during the stabbing 394 The defence criticised the prosecution for challenging the evidence of Prof Coyle and Prof Morris on the basis that Ms Rigney was unable to give an account of any symptoms she experienced at the time of the stabbing. The defence argued that such a requirement would preclude any person unable to remember the charged offending from being able to satisfy the mental incompetence defence, 9 It is argued Ms Rigney is unlikely to have sourced the cannabis from within the Luis premises, noting the short space of time within which the stabbing occurred, as well as the absence of evidence that Ms Rigney entered the house. -- 90 of 114 -- [2025] SASC 80 Bampton J 89 and that there is no authority to support this interpretation of the law. I understood the prosecution to be highlighting the absence of evidence of psychotic phenomenology at the time of the stabbing, whether from a self-report or collateral evidence. Contrastingly, it was my impression that both Prof Coyle and Prof Morris simply determined that because Ms Rigney had a severe mental impairment, she satisfied the s 269C test. 395 The defence also pointed out that Dr Nambiar and Dr Ferris initially gave opinions that Ms Rigney was mentally incompetent to commit the offence in the absence of an account from her as to any symptoms she was experiencing at the time of the stabbing. The defence said that given their approach substantially mirrors the reasoning process adopted by Prof Coyle and Prof Morris, the criticism of Prof Coyle and Prof Morris should be rejected. I disagree. Both Dr Nambiar and Dr Ferris noted the lack of evidence of psychotic symptoms at the time of the stabbing, acknowledged the limitations of their opinions, and revised their conclusions as to mental competence upon receipt of further information. Expertise and experience of Prof Coyle and Prof Morris 396 While acknowledging that Prof Coyle and Prof Morris have completed fewer assessments of mental competence and none in South Australia, the defence contended that the other experts’ greater experience may not correspond with improved performance. The defence relied on three journal articles, in which the authors argue that feedback on the accuracy of decisions is critical in producing learning through experience, with one article stating that “years of experience and involvement in previous investigations or prosecutions … [are] not necessarily strong or direct indicators [of expertise]”. The defence said: Mere exposure to, or experience with, a given procedure or activity does not in itself confer expertise in the sense of superior performance. The Court may consider that practitioners conducting mental competency assessments may not receive feedback as to the objective accuracy of their findings on mental competence, compared to other facets of medical work where a known ground truth can be more easily ascertained. (citations omitted) 397 The defence also pointed to the contention in one article that while “skilled intuition is a widely discussed feature of expertise, both experts and non-experts also engage in intuitive but imperfect automatic responses, susceptible to heuristics and biases that undermine outcome success”. 398 The defence also said that criticism of Prof Coyle and Prof Morris based on lack of experience is undermined by the substantial agreement between them on the one hand, and Dr Nambiar, Dr Ferris, and Dr Furst on the other. Dr Nambiar’s change of position 399 The defence criticised Dr Nambiar for revising his opinion based on his view that Ms Rigney was not exhibiting psychotic symptoms during the second police interview. The defence said that this conclusion is inconsistent with those of each -- 91 of 114 -- [2025] SASC 80 Bampton J 90 other expert including Dr Ferris, who detailed in her report dated 23 March 2021 the indicia of psychosis she considered were present during the interview. The defence pointed out that while Dr Ferris revised her opinion on mental competence, she maintained that Ms Rigney was “experiencing episodes of perceptual disturbances” during the second police interview. 400 The defence also criticised Dr Nambiar’s statement that the absence of psychotic symptoms during the second police interview made it less likely that Ms Rigney was acutely psychotic at the time of the stabbing. The defence pointed to Dr Furst’s opinion that if Ms Rigney had been psychotic at the time of the second police interview, she may have been floridly psychotic at the time of the stabbing, given that symptoms of psychosis can wax and wane. 401 I noted that I asked Dr Furst whether, notwithstanding the possibility that Ms Rigney was floridly psychotic at the time of the stabbing, he maintained his opinion that there was no evidence of her acting on a delusional belief as a result of her schizophrenia. Dr Furst’s response was: A. Yes, I think that my opinion there remains the same. (A) I think it’s absolutely certain that she has psychosis, I think she had active psychosis, the question for me was whether she was so floridly psychotic that she can’t remember what happened and something internal triggered this offence and, on the other hand she was psychotic but not floridly psychotic at the time of the offence and there was something else that happened in that interaction and then she’s had an emotional reaction or behavioural reaction which was probably exacerbated by her schizophrenia, but not to the point of being mentally incompetent. Q. So you maintain your view that she does not have the defence available to her. A. I don’t think I can say it’s more likely than not. I’m afraid I’m sort of – it’s very close, but certainly I don’t feel like there’s enough there to say that I’m more confident that it’s more likely than not. 402 The defence said that Dr Nambiar’s opinion is not only contradicted by the other experts but does not take into account the fact that symptoms of psychosis can wax and wane. 403 The defence submitted that if the Court finds either that Ms Rigney was psychotic during the second police interview or that florid psychosis at the time of the stabbing could have dissipated by this time, it should not be accepted that Ms Rigney’s presentation justified Dr Nambiar’s change in opinion. The defence says that in such circumstances, Dr Nambiar’s revised opinion should be rejected. Ms Rigney’s false account of the stabbing 404 The defence criticised the prosecution’s contention that Ms Rigney gave a false account that she witnessed Maria Luis being stabbed by someone else because she realised that she was criminally responsible for her death, which the defence said is a “dangerous and unwarranted” submission. The defence pointed to the other explanations for the false account such as those posited by Prof Coyle. -- 92 of 114 -- [2025] SASC 80 Bampton J 91 Dr Ferris’ change of position 405 The defence pointed out that while the issue of whether Ms Rigney was deliberately withholding information about her thought processes, behaviour and possible psychotic symptoms at the time of the stabbing was central to the revision of Dr Ferris’ opinion, it was not considered significant by the other experts. The defence referred to Dr Nambiar in this context, who initially regarded Ms Rigney as mentally incompetent even though he considered that she may have been feigning lack of memory about the stabbing. 406 The defence submitted that Dr Ferris’ evidence is inconsistent in that she stated that Ms Rigney refused to answer questions about the stabbing during interviews prior to 22 July 2021, whereas her report of 21 August 2020 described Ms Rigney as forthcoming in the interview even though she became “somewhat distracted” after 90 minutes. 407 The defence criticised Dr Ferris’ reliance on new information obtained during her interview of Ms Rigney on 22 July 2021, contending that Ms Rigney had consistently asserted that she could not recall the stabbing, that she provided no new information during this interview, and that the only change was in her demeanour. 408 The defence also challenged Dr Ferris’ reliance on inconsistencies between accounts provided by Ms Rigney, including whether she had obtained drugs from Maria Luis in the past. The defence pointed out that Dr Ferris was aware of these inconsistencies by the time she prepared her second and third reports, in which she maintained the view that Ms Rigney was mentally incompetent. The defence also submitted that Dr Ferris must have regarded this inconsistency as immaterial, noting the statement in her report dated 30 April 2021 that Ms Rigney’s “recollection and information were in keeping with history given to me on previous recent assessments”. It was submitted Dr Ferris confirmed in cross-examination that she did not consider the inconsistency to be significant. 409 The defence noted Ms Rigney told Dr Ferris that she had no recollection of depositing the backpack on the front lawn of a property nearby to the Luis premises but told Dr Furst that she did have such a recollection. The defence said that Dr Ferris could not have taken this inconsistency into account at the time she revised her opinion because Dr Furst was not given this information until after Dr Ferris produced her final report. 410 The defence acknowledged that it is uncontroversial that Ms Rigney’s mental state improved greatly following treatment in JNH. However, the defence said that it is difficult to understand the relevance of this fact to Ms Rigney’s mental competence at the time of the stabbing, noting that while she was better able to engage with Dr Ferris’ questions during the interview in July 2021, no new information was provided by Ms Rigney and she continued to maintain a lack of memory. -- 93 of 114 -- [2025] SASC 80 Bampton J 92 411 Overall, the defence criticised Dr Ferris for failing to explain how her clinical experience assisted in revising her opinion. Referring to academic literature regarding the limited insight people have into their own decision-making and the dangers of opinions being subconsciously affected by external or irrelevant factors, the defence submitted that Dr Ferris’ justifications for changing her position (namely inconsistencies, new information and clinical experience) are “retrospective rationalisations”. 412 The defence submitted that Dr Ferris’ change of opinion assumes that the sole explanation for Ms Rigney’s lack of self-report is that she remembers her conduct and state of mind at the time of the stabbing but has deliberately or wilfully refused to disclose it because she knows that she is criminally responsible for Maria Luis’ death. 413 The defence said there are other explanations for Ms Rigney’s lack of self-report including that she may not remember the stabbing due to mental impairment. The defence submitted that the Court could not safely make a finding that Ms Rigney remembers the stabbing given the evidence of possible clinical explanations for lack of memory, including “trauma from the incident itself affecting the laydown of the memory engram, hyperarousal associated with psychosis, intoxication, dissociation associated with PTSD, degradation of brain function associated with schizophrenia or a combination of the above”. 414 The defence submitted further that it does not necessarily follow from a finding that Ms Rigney remembers the stabbing that she is mentally competent. Without inviting the Court to determine which might be operating in Ms Rigney’s case, the defence pointed to possible explanations for Ms Rigney not being forthcoming that would still be consistent with incompetence, including feeling confused, embarrassed, ashamed or traumatised by her symptoms or what she remembers doing, feeling paranoid about how an account might be used against her, feeling paranoid that she will get ‘the ghosts’ into trouble, or fearing being held responsible for something she does not understand or cannot explain. 415 The defence said that Dr Ferris does not appear to have sufficiently considered these issues and that it would be difficult for the Court to speculate about why Ms Rigney has declined to discuss the stabbing. Further, the defence pointed out that Dr Ferris initially considered Ms Rigney to have been mentally incompetent at the time of the stabbing notwithstanding uncertainty about whether her claimed memory loss was genuine, whereas her opinion later changed only once she had formed the view that Ms Rigney remembered the stabbing. Admissibility of Dr Ferris’ evidence regarding memory 416 In R v Bonython (“Bonython”),10 King CJ said: 10 (1984) 38 SASR 45 at 46-7. -- 94 of 114 -- [2025] SASC 80 Bampton J 93 Before admitting the opinion of a witness into evidence as expert testimony, the judge must consider and decide two questions. The first is whether the subject matter of the opinion falls within the class of subjects upon which expert testimony is permissible. This first question may be divided into two parts: (a) whether the subject matter of the opinion is such that a person without instruction or experience in the area of knowledge or human experience would be able to form a sound judgment on the matter without the assistance of witnesses possessing special knowledge or experience in the area, and (b) whether the subject matter of the opinion forms part of a body of knowledge or experience which is sufficiently organized or recognized to be accepted as a reliable body of knowledge or experience, a special acquaintance with which by the witness would render his opinion of assistance to the court. The second question is whether the witness has acquired by study or experience sufficient knowledge of the subject to render his opinion of value in resolving the issues before the court. 417 The defence pointed to Christie v The Queen,11 in which the Court addressed the admissibility of a psychiatrist’s opinion that the appellant had been untruthful:12 Thirdly, the expression of an opinion as to the truthfulness of the appellant is objectionable for two other reasons. Truthfulness is a question for the jury and the jury required no expert assistance to determine the issue. There was no matter which the jury could not observe for itself and which required expert assistance. Moreover, the opinion itself is not an expert opinion at all. It is in the nature of a personal opinion and is therefore irrelevant and inadmissible. 418 The defence also referred to Lewis v The Queen:13 There is a tendency amongst academics, professionals and others who develop skills in a particular area to mystify their field, often by the use of what seems to the outside to be arcane language. It is the role of a prosecutor to strip forensic evidence of its mystery so far as is possible; trial by expert must never be allowed to take the place of trial by jury. The inability to articulate the principal tenets that need to be understood, to describe in ordinary language the methods used and the reasons that point to a particular conclusion, these are the hallmarks of unreliable science and the not-so-qualified expert. 419 The defence submitted that an expert’s opinion carries no weight and is inadmissible unless the process by which their conclusions are drawn is expressed in a manner that permits their reliability to be scrutinised.14 420 The defence accepted that Dr Ferris is a qualified psychiatrist. However, the defence said her opinion that Ms Rigney was feigning memory loss regarding the stabbing does not satisfy part (a) of the test as set out by King CJ in Bonython, as the Court can make a sound judgement on this matter without expert assistance. Further, the defence submitted there is not sufficient evidence of the clinical experience purportedly employed by Dr Ferris in drawing this conclusion to satisfy part (b). 11 [2005] WASCA 55. 12 [2005] WASCA 55 at [97] (McKechnie J, Le Miere and Jenkins JJ agreeing). 13 (1987) 88 FLR 104 at 124 (Maurice J), quoted in Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705 at [73] (Heydon JA). 14 Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705 at [85], quoting with approval HG v The Queen (1999) 197 CLR 414 at [41] (Gleeson CJ). -- 95 of 114 -- [2025] SASC 80 Bampton J 94 421 The defence characterised Dr Ferris’ view that Ms Rigney was deliberately withholding information about the stabbing as merely a “belief” that she was lying. The defence said that Dr Ferris had come to this conclusion from Ms Rigney answering some questions “openly and freely” but “shutting down [and] refusing to answer” others, which inference could be drawn by a trier of fact without the assistance of a psychiatrist. 422 The defence also submitted that assessing truthfulness is not within the domain of a psychiatrist in circumstances where there is no indication or explanation that opinions on this matter are based on relevant specialised knowledge, training, study, criteria, or experience. By reference to Makita, the defence said that the factual basis for Dr Ferris’ opinion needed to have been clearly expressed, then proved. The defence noted that the four other experts were careful to either avoid expressing a view on whether Ms Rigney was lying or, in the case of Prof Coyle, identified the criteria against which he assessed Ms Rigney’s truthfulness and qualified his opinion. 423 The defence submitted that whether Ms Rigney has memory of the stabbing is a question for the trier of fact, and that Dr Ferris’ conclusion, as “nothing more than an expression of personal opinion”, is inadmissible, along with “the opinion based upon it, namely, that Ms Rigney was mentally competent”. The defence alternatively invited the Court to reject Dr Ferris’ revised opinion as “insufficiently probative”. In either event, the defence said that Dr Ferris’ earlier opinion to the effect that Ms Rigney was mentally incompetent should be accepted. Prosecution submissions 424 The prosecution accepted that Ms Rigney had a mental impairment, namely schizophrenia, at the time of the stabbing, but submitted that s 269C(1) requires a finding of “total incapacity, not just a finding of some limitation [in one of the ways identified by ss 269C(1)(a)-(c)] as a result of her mental impairment”. 425 The prosecution said there is insufficient evidence that Ms Rigney was suffering psychosis that caused the stabbing. The prosecution pointed out that there is no evidence of Ms Rigney’s thought processes at the time of the stabbing, and that the only evidence that Ms Rigney had no memory of the stabbing is her self-report to doctors. The prosecution relied on Ramsay v Watson15 in support of the submission that what Ms Rigney told doctors is only admissible to explain their opinions, and the weight the Court can place on such opinions is limited in the absence of direct evidence of the underlying facts. Specifically, the prosecution submitted that it would be impermissible to conclude that Ms Rigney did not remember the offending in the absence of such evidence. 15 (1961) 108 CLR 642. -- 96 of 114 -- [2025] SASC 80 Bampton J 95 Collateral evidence supporting mental competence 426 The prosecution pointed out that Ms Rigney had attended the Luis premises earlier on the day of the stabbing and that Ms Rigney said during the second police interview that she did so to purchase cannabis, which it was submitted supports a conclusion that Maria Luis did not supply Ms Rigney with cannabis on the first occasion. The prosecution noted the evidence that Maria Luis had previously refused to sell cannabis to Ms Rigney, and that the evidence suggests a motive to kill, being drug-related conflict. 427 The prosecution submitted that Ms Rigney went to “some effort” to attend Cash Converters to obtain a loan, which also necessitated her attending Service SA to secure 100 points of identification. The prosecution pointed out that Ms Rigney was not presenting as psychotically unwell or intoxicated at this time, could go through the administration process, and could communicate appropriately with staff. 428 The prosecution pointed to the fact that 34 stab wounds were inflicted by Ms Rigney and said that this was not a “compulsive mechanical” attack, noting the opinions of Dr Ferris and Dr Furst that the attack on Maria Luis is consistent with offending by a mentally competent person. 429 The prosecution submitted that the evidence of Ms Rigney’s conduct subsequent to the stabbing demonstrated “a presence of mind” and a desire to avoid being linked to the stabbing. The prosecution said that her immediate departure towards her home without collecting the backpack she had deposited nearby suggests that she was “moving with a degree of focus away from the scene”. The prosecution invited the Court to infer that Ms Rigney had brought a weapon with her to the Luis premises and concealed it after the stabbing, which the prosecution said demonstrates “presence of mind” to distance herself from the crime. Finally, the prosecution said the evidence suggests that Ms Rigney burned a long-sleeved tartan shirt that was at least in her possession around the time of the stabbing, even if it is not possible to conclude that she was wearing it at the time, which the prosecution submitted is consistent with an attempt to “cover her tracks”. Criticisms of Prof Coyle and Prof Morris 430 Overall, the prosecution submitted that Dr Nambiar, Dr Ferris, and Dr Furst have a greater level of experience in clinical assessment and treatment of people suffering from paranoid schizophrenia, which affords their opinions greater weight. 431 The prosecution criticised Prof Coyle and Prof Morris for concluding that Ms Rigney lacked mental competence on the basis that she did not know whether the conduct was wrong and/or was totally unable to control her conduct. The prosecution submitted that the use of the and/or formulation is unclear and belies a lack of experience with the s 269C test. The prosecution said that opinions expressed in such a way cannot be accepted. Further, notwithstanding Prof Morris’ -- 97 of 114 -- [2025] SASC 80 Bampton J 96 denial that he was influenced by Prof Coyle’s report, the prosecution suggested that owing to Prof Morris’ limited experience in applying the test, he had “a lack of confidence in reaching a different conclusion [to Prof Coyle]”. 432 The prosecution said Prof Coyle’s criticism of Dr Furst’s conclusion “[undermines] the soundness of his understanding of the onus and presumption”. 433 The prosecution pointed to a lack of evidence of irresistible command hallucinations at the time of the stabbing or at any other time. 434 The prosecution rejected Prof Coyle’s assertions of heuristic bias, pointing out it is appropriate for experts to consider assumptions and reevaluate their opinion when provided with new materials. The prosecution submitted a lack of bias is evident from the fact that Dr Nambiar and Dr Ferris rejected some suggestions in the DPP letter. The prosecution also pointed out that Dr Furst concluded that the s 269C defence was not available without having received the letter. The prosecution noted that Dr Nambiar made plain that his change in opinion was consequent upon having seen the video of the second police interview, which the prosecution said “may have some impact on an expert”. In this regard, I note Dr Furst said in relation to the first and second police interviews: I think the difficulty I have is her presentation the following day was different. So quite often when someone’s been arrested for an incident, you know, and you’ve got that video footage, that is the most useful thing to be able to tell what their mental state was at the time of the offence. The difficulty I have for this case was that her mental state seemed to change quite significantly from that night to the next day and she had admitted that she had been smoking cannabis prior to the police arriving. So that made it very difficult for me to say ‘Well, the mental state that I saw on the video is predominantly due to her psychosis or is it partly due to her psychosis with a large dose of cannabis effect on top’. 435 The prosecution also highlighted the absence of evidence of psychotic phenomenology linking to the offence, which the prosecution said was critical to the ultimate forensic conclusions of Dr Nambiar, Dr Ferris, and Dr Furst but was not considered by Prof Coyle. 436 The prosecution said that in the absence of direct evidence of Ms Rigney’s lack of memory, limited weight can be ascribed to Prof Coyle and Prof Morris’ opinions founded on her self-report. The prosecution further submitted that Prof Coyle and Prof Morris’ opinions about the link between trauma, schizophrenia and memory are of limited utility in this context. 437 The prosecution said that Prof Coyle’s approach fails to grapple with surrounding evidence and assumes that because Ms Rigney had schizophrenia, she was necessarily unable to engage in wilful behaviour. The prosecution submitted that this significantly limits the weight that can be afforded to his evidence. The prosecution said that Prof Coyle sometimes assumed that Ms Rigney’s behaviours were due to schizophrenia without a basis to do so and characterised some of his conclusions as rushed, including the assertion (which was later partially retracted) -- 98 of 114 -- [2025] SASC 80 Bampton J 97 that Prof White’s report is “completely inconsistent” with Ms Rigney’s conduct at the time of her arrest being the product of cannabis consumption. 438 The prosecution referred to Prof Coyle’s opinion that Ms Rigney giving an account of Maria Luis being stabbed by another person indicated that she was psychotic and had a delusional belief system, saying that this view is contradicted by Dr Nambiar, Dr Ferris, and Dr Furst, whose opinions ought to be preferred on the basis of their greater level of training and experience with psychosis. The prosecution also criticised Prof Coyle’s conclusion that Ms Rigney might have been trying to make sense of what had happened, saying that this opinion is undermined by the fact that aspects of Ms Rigney’s account are not supported by other evidence. The prosecution said that Ms Rigney’s report to police is “capable of being construed as an exculpatory account”. 439 The prosecution submitted that weight should be given to Dr Nambiar’s opinion that Prof Coyle’s conclusions regarding brain damage are speculative. 440 It was submitted that Prof Morris’ evidence regarding the lead-up to the stabbing and Ms Rigney repeatedly targeting Maria Luis, including that there was no evidence that she held a delusional belief system about Maria Luis and may simply have disliked her, “sits uncomfortably” with a conclusion of incompetence. 441 The prosecution pointed out that Prof Morris said in an email to Ms Rigney’s solicitor that Ms Rigney “aggressively targeted” Maria Luis, whereas his report said that she was “indiscriminately behaving aggressively”. The prosecution suggested that the statement in the email is inconsistent with a conclusion that Ms Rigney was incompetent. The psychiatrists called by the prosecution 442 The prosecution invited the Court to give weight to the opinions of Dr Nambiar, Dr Ferris, and Dr Furst, who the prosecution said each have extensive relevant experience and each rely on the same matter: the absence of evidence of a link between the stabbing of Maria Luis and Ms Rigney’s mental impairment, such as command hallucinations or delusional thinking. 443 With respect to Dr Nambiar and Dr Ferris changing their positions, the prosecution submitted that experts are permitted to do so in the face of fresh evidence and that an expert revising their opinion is not in itself of probative value. The prosecution said that in fact, this may demonstrate “a preparedness to adopt new considerations and reflect … consistent with the obligations of an expert”. 444 The prosecution submitted that Dr Nambiar’s initial opinion was not strongly held and again, referred to his explanation that his opinion changed after viewing the second police interview. 445 It was submitted that Dr Ferris’ conclusion regarding Ms Rigney’s denial of memory being evasive, which was reached on the basis that no improvement in -- 99 of 114 -- [2025] SASC 80 Bampton J 98 her memory was reported despite an improvement in her condition generally, is consistent with common sense as well as expert understanding. The prosecution also said that this conclusion is supported by Ms Rigney initially giving an exculpatory account then later denying memory of the stabbing. Discussion 446 Ms Rigney has chronic, treatment-resistant schizophrenia characterised by delusions of pregnancy, infestation, rape, and ghosts, as well as chronic auditory and visual hallucinations. She also has borderline and anti-social personality traits, a history of substance abuse, and complex childhood trauma. As noted above, Ms Rigney has reported she was the victim of child sexual abuse, and it is likely that she has PTSD. 447 The evidence suggests Ms Rigney had chronic symptoms of schizophrenia for more than a year prior to the stabbing, although her cannabis and methamphetamine use led psychiatrists to diagnose her with drug-induced psychoses. Nevertheless, there is no dispute that at the time of the stabbing, she was suffering from chronic paranoid schizophrenia that arose independently of any illicit drug use. 448 I find that at the time of the stabbing, Ms Rigney had a mental impairment, namely, treatment-resistant schizophrenia. Although the defence submitted that Ms Rigney also had PTSD and that this exacerbated the symptoms of her schizophrenia, it is not necessary that I make a finding about whether Ms Rigney had PTSD. In resolving this matter, I must consider the evidence of how Ms Rigney’s schizophrenia was affecting her at the time of the stabbing, and nothing appears to turn on whether any symptom she might have been suffering was the result of her schizophrenia or her schizophrenia being exacerbated by PTSD. 449 I must apply the test prescribed by s 269C(1) to decide whether, on the balance of probabilities, Ms Rigney has displaced the presumption of mental competence by establishing that, at the time of the stabbing, she satisfied s 269C(1)(a), (b) or (c). 450 There is no suggestion Ms Rigney did not know the nature and quality of her conduct as prescribed by s 269C(1)(a). 451 The question is whether Ms Rigney has established on the balance of probabilities that her mental impairment was operative at the time of the stabbing to such an extent that it rendered her completely incapable of: 1. reasoning about whether her conduct was wrong as perceived by reasonable people pursuant to s 269C(1)(b).16 The relevant question is whether she 16 R v Childs [2023] SASC 103 at [55]-[56] (Lovell J): -- 100 of 114 -- [2025] SASC 80 Bampton J 99 retained any capacity at the time she stabbed Maria Luis, as distinct from having no capacity, to reason about whether her conduct was wrong as perceived by reasonable people; or 2. controlling her conduct at the time she was stabbing Maria Luis as prescribed by s 269C(1)(c). 452 This matter is complicated by the fact that Dr Nambiar and Dr Ferris changed their opinions regarding the availability of the s 269C defence. While Dr Nambiar considered the defence was available in his first report dated 26 March 2020, he altered his opinion four months later after having viewed the video of the second police interview, as detailed in his report dated 20 July 2020. Dr Ferris, in her reports dated 21 August 2020, 20 September 2020 and 23 March 2021, considered the defence was available and altered her opinion in her report dated 26 July 2021 following a further interview with Ms Rigney. 453 If the trial of the matter had not been vacated in May 2021, the Court would have been faced with the competing opinions of Dr Nambiar and Dr Ferris. I strongly suspect that to assist in resolving this difficulty, the Court would have ordered another psychiatrist to assess Ms Rigney pursuant to s 269WA, just as I did on 27 September 2021 after noting the unusual situation of two psychiatrists having altered their opinions. 454 As I have said, the expert evidence before the Court inevitably leads to a finding that on the balance of probabilities, Ms Rigney suffered from a mental impairment at the time of the stabbing. It is apparent that Ms Rigney suffered from the mental impairment before the stabbing and that she continues to suffer from it. Further, the evidence suggests that at the time of the stabbing, she was likely suffering from psychosis, noting that persons with treatment-resistant schizophrenia have chronic residual psychotic symptoms.17 Her impairment is I turn next to the question of whether the defendant has to establish that he or she had a complete incapacity to know that their conduct was wrong. The text of the section certainly suggests a complete incapacity is the correct test. The note to s 269C(1)(b) specifically excludes from consideration whether the defendant could reason with a moderate degree of sense and composure as set out in Porter. Under s 269C(1)(b) of the Act, the defendant must prove that he or she does not know that their conduct was wrong. The term ‘know’ means understand, appreciate or comprehend. An incapacity to reason rationally as to what is right or wrong according to ordinary standards prevents a person from having the capacity to know that he or she ought not do the act. The wording of the section supports the interpretation that the defendant must establish that, at the time he fired the shots at Mr Evans, his mental impairment resulted in a complete incapacity to reason as to what is right or wrong according to ordinary standards. (Emphasis in original) 17 Dr Nambiar noted in his report dated 28 April 2021: “The term ‘Treatment Resistant’ means that despite medications taken regularly and supervised, she continues to have chronic residual symptoms that consist of delusions and hallucinations”. Similarly, Dr Ferris said in her report dated 20 September 2020 that Ms Rigney suffered from treatment-resistant psychosis with ongoing psychotic symptoms despite having a high dose of depot antipsychotic medication. Dr Furst accepted that Ms Rigney falls within the 25 percent of the population of people with schizophrenia that continue to experience significant symptoms even with clozapine treatment. -- 101 of 114 -- [2025] SASC 80 Bampton J 100 significant, and it took many months to manage in an inpatient setting following the stabbing. She was kept at JNH during the pre-trial period when her fitness to stand trial fluctuated, and it was Dr Nambiar’s opinion that remaining at JNH during the trial would give her the best possible chance of participating in these proceedings. 455 I must keep in mind that whilst Ms Rigney was suffering from a mental impairment at the time of the stabbing and maintains that she has no memory of it, it does not necessarily follow that she has displaced the s 269D presumption. Dr Ferris gave evidence that forensic psychiatrists very regularly assess accused persons who have acute psychotic symptoms but do not satisfy the s 269C criteria, given that there must be a link between their mental impairment and the alleged criminal conduct. She said: So it’s actually not that uncommon for people with treatment-resistant schizophrenia who are psychotic to not automatically get a [s 269C] defence. There needs to be a knowledge of the content of the psychotic thought that leads to that behaviour. 456 It would be contrary to s 269C to simply conclude that because Ms Rigney had a severe, chronic mental impairment, she was precluded from knowing whether her conduct was wrong and/or totally unable to control her conduct. I must find evidence that she was so precluded “in consequence of [her] mental impairment” at the time of the stabbing. Inextricably entwined with this enquiry is the issue of whether there is evidence of a credible, non-psychotic alternative explanation for Ms Rigney’s conduct. In this respect, I note Dr Furst’s evidence that in resolving the question of mental competence, he turned his mind to whether Ms Rigney was floridly psychotic such that something internal triggered the stabbing, or whether Ms Rigney was psychotic but not floridly psychotic and had a behavioural reaction that was exacerbated by her schizophrenia. 457 Ms Rigney’s difficult-to-control mental impairment, history, need to remain at JNH during the trial, and reported lack of memory of the stabbing, along with the conflicting expert opinions, make this a complicated matter to decide. Dr Furst expressed the view that this s 269C investigation is a difficult, borderline matter, in which he ultimately concluded that “it’s very close, but certainly I don’t feel like there’s enough there to say that … it’s more likely [that the defence is available to her] than not”. Similarly, the reservations expressed by Dr Nambiar and Dr Ferris in their earlier reports reveal how finely balanced this matter is regarding the displacement of the presumption. 458 At this point, I note that contested Part 8A matters are not common. Most matters resolve either in circumstances where the prosecution concedes that the s 269C defence is enlivened, or the defendant’s plea of not guilty by reason of mental incompetence is not maintained. 459 In resolving this matter, I must decide the ultimate question of mental competence assisted by the experts called by the prosecution and defence. In -- 102 of 114 -- [2025] SASC 80 Bampton J 101 R v Childs (“Childs”),18 Lovell J discussed the roles of the judicial officer and the expert witnesses in Part 8A matters:19 Evidence from a properly qualified expert is generally more reliable than a lay person’s opinion (including a judicial officer’s) because an expert has more information relevant to the matter and the experience of evaluating such information. Clearly a judicial officer must have regard to that. However, I cannot “outsource” the decision and simply defer to the expert evidence. I must exercise my own independent judgement in arriving at a conclusion. There is a distinction between intellectual autonomy and intellectual individualism. Intellectual autonomy is not incompatible with relying on the thinking of others; thinking for oneself and relying on experts are not exclusive options. That is, thinking for oneself does not mean thinking by oneself. It is important that appropriate weight be given to expert evidence not because judicial officers and experts have the same role but precisely because they have different roles. It is my role to decide the ultimate question of mental competence. The role of the experts is to provide an opinion that will assist me in deciding that question. … When cross-examined, both doctors were able to explain clearly and logically how they had considered those facts that pointed away from their opinions and why the inferences that could be drawn from those matters did not change their final opinion. In doing so, they relied on their expertise to explain how facts, which may appear to a lay person to perhaps be contrary to their opinions, are capable of a quite different interpretation. A good example lies in the interpretation of the fact that the defendant was clearly aware, very quickly, that in shooting Mr Evans, he had performed an illegal act. Both Dr Haeney and Dr Furst were convincingly able to explain how the defendant possessing that state of mind, but suffering from schizophrenia, would still not necessarily have any capacity to determine right from wrong as perceived by reasonable people. Both Dr Haeney and Dr Furst accepted that their opinions are not entirely objective. In reasoning towards their opinions, both doctors accepted that part of that process included personal judgement based on their training and experience. In psychiatry, experience and training play an important role in reaching any conclusion. That is, there is a degree of subjectivity in reaching conclusions and this case is perhaps a good example of that. Both Dr Haeney and Dr Furst explained that there are matters which may demonstrate an understanding by a person of sound mind, but which may not do so if a person is incapable of reasoning rationally because of a mental impairment. I have no expertise as to when the normal shades into the abnormal in that context. (Citations omitted) 460 Dr Furst spoke about the video footage of a police interview captured soon after a person’s arrest being “the most useful thing to be able to tell what their mental state was at the time of the offence”. Likewise, Dr Nambiar said that when he assessed Ms Rigney for his first report, the first police interview: … was the closest in terms of information that I had around the time of the offence that I formed that opinion on and that opinion was that she had symptoms of schizophrenia and 18 [2023] SASC 103. 19 [2023] SASC 103 at [88]-[99]. -- 103 of 114 -- [2025] SASC 80 Bampton J 102 more likely than not, because there was no other evidence to challenge that in my mind, that it was related to the offence. (Emphasis added) 461 Dr Nambiar considered that the nature of the attack was not necessarily more consistent with a psychotic motive than a non-psychotic motive, but at the time of his first report, with the lack of information he had, he said he gave Ms Rigney the benefit of the doubt. 462 Dr Nambiar explained that he altered his opinion regarding mental competence upon viewing Ms Rigney’s presentation in the video of the second police interview, which was not provided to him until after he prepared his first report. 463 Having viewed the video, he said he could not detect evidence of symptoms of schizophrenia. He explained that specific questions would have to have been asked of Ms Rigney to try and draw out symptoms if they were present. But if she were floridly psychotic, he said the symptoms would have been obvious. Dr Nambiar explained that in his experience of assessing accused persons suffering from mental impairments under s 269C, there is usually evidence of a delusional thought linked to the alleged conduct or there are persistent command hallucinations that the person finds overwhelming and unable to resist, and that there was no such evidence in the second police interview. He said the video of the second police interview, which was also recorded very close to Ms Rigney’s arrest, provided him some insight into her mental state and, in the context of all the other information, caused him to change his mind. 464 Dr Nambiar identified evidence of a credible, non-psychotic alternative explanation for the stabbing. That is, he considered that Ms Rigney’s relationship with Maria Luis, the perceived conflict between them, and exculpatory explanations given by Ms Rigney for her attendance at the Luis home appeared to be more consistent with an impulsive episode of behaviour. He therefore said Ms Rigney’s presentation during the second police interview gave more weight to a conclusion that she knew her conduct was wrong. I infer that had Dr Nambiar viewed the video of the second police interview at the time he prepared his first report, he might not have concluded the s 269C defence was available. 465 As regards Ms Rigney’s memory, Dr Nambiar stated in his report dated 8 February 2021: Ms Rigney appears to have a relatively intact memory with regards to incidents that have occurred in her past that she chooses to raise or focus on. There does not appear to be a generalised inability to recall details of past events. Her current inability to recall the events of the day of the offence is in contrast to her ability to recall some details when I interviewed her in 2020. This inability is not due to an impairment. I would also add that although she claimed on her most recent interviews with me during her current admission to James Nash House that she has no recollection, I note that in my -- 104 of 114 -- [2025] SASC 80 Bampton J 103 first interview with her at the Adelaide Womens Prison in March 2020, her memory of events and version of events were much more detailed and she was able to describe those details with much conviction as compared to the effort she appears to be making now. (Emphasis added) 466 I am satisfied that Dr Nambiar applied the correct test pursuant to s 269C and I accept his ultimate opinion, which he has explained logically and clearly, including the reasons for his change of opinion. At this juncture, I point out I do not accept the allegations of heuristic bias levelled by Prof Coyle, the presence of which he asserts is to be inferred from Dr Nambiar’s change of opinion following receipt of the DPP letter. It is not unusual in either the civil or criminal jurisdiction for experts to be asked to adopt assumptions or for them to revise their opinions in light of fresh information. I also reject Prof Coyle’s criticism based on the suggestion that repeated questioning of Ms Rigney by Dr Nambiar and Dr Ferris raises the possibility of post-event contamination of memory. Dr Nambiar and Dr Ferris necessarily had to question Ms Rigney during many assessments to provide Court-ordered reports regarding her fitness to stand trial and mental competence. Dr Furst, Prof Coyle, and Prof Morris also had to question Ms Rigney about the stabbing in preparing their reports. Repeated questioning during assessments is integral to the role of forensic psychiatrists. Overall, Prof Coyle’s assertions of heuristic bias and criticisms regarding repeated questioning by the forensic psychiatrists belie his purported experience in giving expert evidence regarding mental incompetence in criminal matters. 467 Dr Ferris explained that a psychiatrist assessing whether a person satisfies the s 269C criteria needs to have knowledge of the content of the person’s psychotic thought that is linked to the conduct. Dr Ferris conceded that she did not know the content of any psychotic thought that led to the stabbing when she concluded that the s 269C defence was available to Ms Rigney in her first three reports. She said: No … it is very [multifactorial] when considering the [s 269C] legislation. It is [multifactorial] in regards to the clinical, in that the clinical assessment that you are doing, in terms of the collateral information, in terms of the questions, in terms of the subconscious response and [non-verbal] communication. It is not always totally to do with the content of the psychotic belief. It can also [have] to do with the thought processes as well. 468 Dr Ferris stated that in most cases, information regarding psychotic thought is obtained from the defendant and on other occasions, collateral information is very clear. For example, the person may have been yelling delusional content just before an alleged offence. 469 Dr Ferris gave evidence, having reviewed Ms Rigney in July 2021, that on balance, she was of the view that Ms Rigney remembers and is able to speak more freely about what occurred at the time of the stabbing. She said she formed that opinion based on her nuanced questioning of Ms Rigney, Ms Rigney’s clinical presentation, and Ms Rigney being able to speak about other events openly and freely yet shutting down and refusing to respond to questions in relation to the -- 105 of 114 -- [2025] SASC 80 Bampton J 104 stabbing. Dr Ferris also relied on the clinical notes of Ms Rigney’s progress on the ward as an inpatient, where there had not been any concerns about memory disturbance. 470 I formed the impression that Dr Ferris was, at times, defensive in her evidence, which was perhaps in response to the rigorous cross-examination by Ms Rigney’s counsel. Indeed, on one occasion, I asked counsel to be more temperate in his questioning of Dr Ferris. Further, when pressed to explain her decision-making and thought processes, Dr Ferris sometimes struggled to clearly articulate how her opinions were informed, making many references to reliance on her clinical experience. 471 Dr Ferris’ views that rely on her clinical experience comprise what Lovell J identified in Childs as the subjective part of an expert’s opinion based on their training and experience. As Lovell J stated, in psychiatry, experience and training play an important role in reaching any conclusion and there is a degree of subjectivity in doing so. Having said this, Dr Ferris’ opinions that Ms Rigney is able to give “truthful information” and “truthful answers”, and that “she may not [be] telling the truth”, are problematic. The defence contended that sound judgements regarding Ms Rigney’s truthfulness can be drawn by a trier of fact. I do not accept this. Clearly, I cannot assess whether Ms Rigney has been truthful in circumstances where she has not given evidence. The defence was also critical of the fact that Dr Ferris came to these conclusions from Ms Rigney answering some questions “openly and freely” but “shutting down [and] refusing to answer” other questions. It may be that in describing Ms Rigney as not being “truthful”, Dr Ferris was referencing her assessment that Ms Rigney was reluctant to discuss a non-psychotic motive or that she was being evasive. However, Dr Ferris struggled to articulate the basis for her opinion that Ms Rigney was able to provide a more detailed account of the stabbing. More importantly, Dr Ferris did not make plain in her report or in evidence why, in her view, Ms Rigney feigning memory loss militates against a conclusion that she was mentally incompetent at the time of the stabbing. She posited in cross-examination that if Ms Rigney were withholding information due to the guardedness aspect of her schizophrenia, it would mean that Ms Rigney understood her mental state, the wrongfulness of her actions, and the consequences of her conduct. This opinion and the foundation of it was not explored further, but it is difficult to see how any of these conclusions necessarily follow from Ms Rigney wilfully refusing to disclose information about the stabbing. 472 In applying the s 269C test in her first three reports, Dr Ferris variously stated she did not have any self-report from Ms Rigney about her mental state, thought processes, motive, or the presence or absence of psychotic symptoms at the time of the stabbing, and that it was possible Ms Rigney was feigning memory loss. Notwithstanding this, as Dr Furst suggested, Dr Ferris’ first three reports, like Dr Nambiar’s first report, appear to presume from the evidence regarding thought disorder that Ms Rigney was unable to reason about wrongfulness. However, as Dr Furst also pointed out, whilst Ms Rigney presented as quite disorganised -- 106 of 114 -- [2025] SASC 80 Bampton J 105 immediately after the stabbing, it does not necessarily follow that the s 269C defence is available. 473 Dr Ferris ultimately explained in evidence that there must be a link between a defendant’s psychotic thought processes and the alleged criminal conduct for the s 269C criteria to be satisfied. I accept this aspect of her evidence, and I am assisted in doing so by the clearly articulated, reasoned opinions of Dr Nambiar and Dr Furst on this subject. The need to identify a link between Ms Rigney’s mental impairment and the stabbing, such as evidence of a delusional motive, evidence of command hallucinations, evidence from a source proximate to or at the time of the stabbing, or some other explanation deriving from psychosis for Ms Rigney’s conduct, which would have rendered her completely unable to reason about the wrongfulness of the stabbing or control her conduct, is a consistent theme in the evidence of Dr Nambiar, Dr Ferris and Dr Furst. I accept Dr Ferris’ evidence that she was unable to identify the content of any psychotic thought linked to the stabbing. However, in contrast to Dr Nambiar and Dr Furst, Dr Ferris did not discuss the question of a credible, non-psychotic alternative explanation for the stabbing. Her evidence was confined to not having a self-report from Ms Rigney or other evidence regarding any psychotic symptoms she was experiencing at the time of the stabbing, and her belief that Ms Rigney was able but unwilling to provide more details. 474 In circumstances where Dr Ferris did not logically and clearly explain the reasons for her change of opinion, deferred to the concept of truth, and did not address whether there was evidence of a credible, non-psychotic alternative explanation for the stabbing, and in circumstances where her earlier reports did not identify a link between Ms Rigney’s mental impairment and the stabbing, I am unable to accept any of her opinions regarding Ms Rigney’s competence. It is therefore unnecessary that I deal with the defence submissions regarding the admissibility of Dr Ferris’ opinion that Ms Rigney was being untruthful in accordance with Bonython. 475 With the benefit of hindsight, given the way Dr Nambiar and Dr Ferris altered their opinions when further information was provided or Ms Rigney’s presentation improved, it would have been preferable for them to have articulated their misgivings regarding competency by giving their opinion but reserving the right to reconsider it if more information became available. An example of such an approach can be found in the opinion of the forensic psychiatrist, Dr Owen Haeney, who reported in Childs that he formed his opinion in respect of mental competence on the balance of probabilities, but acknowledged that there was significant conflicting or inconsistent information from the sources available:20 I am persuaded most by his pre-existing diagnosis of schizophrenia, some contemporaneous evidence of active mental illness, the rather bizarre nature of the attack and the current lack of an alternative plausible motive. However, this opinion is offered 20 [2023] SASC 103 at [65]. -- 107 of 114 -- [2025] SASC 80 Bampton J 106 not without some reservations and I reserve the right to reconsider should new information come to light. (Emphasis added) 476 It also would have been prudent for Dr Nambiar to have avoided explaining his original opinion in terms of giving Ms Rigney the “benefit of the doubt”. In other words, it would have been preferable for him to have adhered to the statutory language of Part 8A when applying the s 269C test and articulating his opinion. 477 Dr Furst noted there is a credible, non-psychotic alternative explanation for the stabbing. He referred to Ms Rigney’s history of buying cannabis from Maria Luis and the evidence of conflict between them in the days leading up to the stabbing. 478 Dr Furst considered it possible that Ms Rigney attempted to purchase or purchased cannabis from Maria Luis, and that a disagreement occurred during that interaction. He said that if such a disagreement had occurred, it is likely that Ms Rigney’s psychotic state would have predisposed her to react in a “paranoid, impulsive and aggressive manner”. Dr Furst stated that in such circumstances, Ms Rigney would have acted on impulse and in a heightened emotional state but nonetheless would have known that her conduct was wrong. 479 Dr Furst noted that there was a gap in Ms Rigney’s report of events between attending Maria Luis’ house to obtain cannabis, going home to smoke it, returning to drop her backpack at the front of the property nearby to the Luis premises, then the police coming to her house. He referred to Ms Rigney giving an account during the second police interview of being present at Maria Luis’ home and witnessing her being stabbed but said that “there was no explanation or anything deriving from her psychosis as to why she would be unable to know that stabbing a person was wrong”. 480 Dr Furst also noted instances of Ms Rigney engaging in violent behaviour while affected by an active psychosis, which he said would be consistent with a predisposition to act aggressively. He described this as a link between her mental illness and the stabbing but reiterated that he “couldn’t find where it went beyond diminished control of behaviour to actually being unable to know wrongfulness or complete inability to control”. 481 Dr Furst also reiterated that it is very rare for a person to satisfy s 269C(1)(c): I think it’s because of the way that test is framed, that they’re sort of wholly unable, you know, totally unable to control and I think the issue there is that of course in a moment, any person who has a high emotional state might, what people might colloquially call lose control. The reality is even in those states, people do have some measure of control. The issue is they choose to, it’s not really a conscious choice, but it’s an allowance of their [emotions] to take over and do those actions. So I think that there is always some measure of control there, otherwise any person might have a momentary loss of control and be considered mentally impaired. -- 108 of 114 -- [2025] SASC 80 Bampton J 107 (Emphasis added) 482 While Dr Furst agreed that Ms Rigney may have considered that Maria Luis had treated her unfairly and given that idea “a prominence that it may not have deserved”, he did not accept that it was more likely than not that Ms Rigney would have reacted psychotically if she had been rebuffed by Maria Luis on the day of the stabbing. He said: I don’t think you can be that clear that it’s because of the psychosis, it’s because of a paranoid interpretation of the events. Certainly people who are psychotic will have a general predisposition, as I said, more fearful, more paranoid, more impulsive, all of those things and so certainly within that context she might have felt like she was being rejected unfairly, but that’s also part of normal day-to-day interaction. That doesn’t necessarily mean it was the psychosis which caused her to react. (Emphasis added) 483 In identifying that the history of conflict between Maria Luis and Ms Rigney may suggest a non-psychotic motive for the stabbing, Dr Furst also noted that violence is commonly associated with drugs, drug deals, and drug debts. Dr Furst agreed the attack on Maria Luis was frenzied but said that a person in a heightened emotional state could react to a situation in a frenzied manner without being psychotically driven. 484 Dr Furst said that the issue was “fairly finely balanced” but that “there just wasn’t enough [evidence] to … make it more likely than not that [Ms Rigney had the] defence and [he] had to balance that against an alternative hypothesis”. 485 Dr Furst explained logically and clearly how he considered the relevant facts, including the collateral information regarding Ms Rigney and her mental impairment, in applying the s 269C test. He also candidly stated that the matter is finely balanced. I am satisfied Dr Furst applied the s 269C test correctly and I accept his opinion. 486 Prof Coyle and Prof Morris concluded that Ms Rigney’s psychopathology precluded her from knowing her conduct was wrong and/or caused her to be totally unable to control her conduct. 487 Prof Coyle said he formed the view that Ms Rigney was “genuine vis-à-vis the history she [had] recounted and her symptoms”. He explained he was of the opinion Ms Rigney was suffering from dissociative amnesia: Because it is very likely to occur in connection with trauma cases following child sexual abuse … all things considered, [it is] the most effective scientifically validated explanation for her inability to be able to recall significant if not all aspects of the night in question. 488 Prof Coyle maintained he had considered alternative explanations for Ms Rigney’s purported inability to recall the stabbing, including wilful denial or avoidance, but contended: -- 109 of 114 -- [2025] SASC 80 Bampton J 108 If one accepts, as everyone has done, that she is suffering from chronic paranoid schizophrenia, then there can be no question of wilful denial or ignorance because of the word ‘wilful’. She did not have the capacity, the mental capacity, to engage in wilful behaviour because that word implies knowing what she was doing. It is completely inconsistent with a diagnosis of paranoid schizophrenia, which she had had for years before this event. (Emphasis added) Prof Coyle argued: Again, in simple terms, we’re talking – and very pragmatic terms, we’re talking about a person who, by definition, suffering from paranoid chronic schizophrenia is not in contact with reality. It is that simple. There can be nothing simpler. We are all agreed that she suffered from chronic paranoid schizophrenia at the time. That’s not an argument. It must proceed from that, but in conjunction with the problems, the interactive, the synergistic problems caused by chronic post-traumatic stress disorder that she was not capable of being in contact with reality at that time. It must … proceed from that. There is no other logical, scientific or clinical explanation. (Emphasis added) 489 Prof Coyle concluded that “it is more likely than not that Ms Rigney was suffering mental impairment due to the conjoint operation of her complex psychopathology”. Prof Coyle determined this precluded her from knowing whether her conduct was wrong and/or rendered her totally unable to control her conduct. Prof Coyle arriving at his conclusion in this way suggests that he merely reasoned from the fact of Ms Rigney’s mental impairment that the s 269C defence is available to her. 490 In response to the suggestion that evidence of psychotic phenomenology at the time of the stabbing must be identified before it can be concluded that the s 269C defence is available, Prof Coyle queried: … how would cogent evidence of Ms Rigney acting on some delusional belief system be obtained when she was suffering from Dissociative Amnesia which interacted with her Chronic, Treatment Resistant Paranoid Schizophrenia, PTSD – as well as Bipolar Affective Disorder according to Dr Ferris – and the sequelae of child sexual abuse? Prof Coyle went on to postulate that Ms Rigney may have suffered from a flashback with derealisation at the time of the stabbing such that she could not distinguish fantasy from reality, which would have, by definition, rendered her mentally incompetent. As Dr Furst pointed out, whilst this possibility cannot be excluded, there is no evidence of it having occurred in this matter and even if there were, it does not necessarily follow that the s 269C defence would be available in such circumstances. 491 Having considered the report and evidence of Prof Coyle, I have concerns about his understanding of the presumption and burden that apply with respect to the mental incompetence test. I refer to his criticism of Dr Furst’s conclusion in this context. I also have reservations in accepting his opinion in circumstances -- 110 of 114 -- [2025] SASC 80 Bampton J 109 where he said that he did not have enough information to conclude that either or both of ss 269C(1)(b) and (c) were satisfied, but nonetheless formulated his opinion in terms of (b) and/or (c) being established. Prof Coyle also remarked on several occasions that Ms Rigney was suffering from a mental impairment due to the conjoint operation of her complex psychopathology. However, it is not the case that Ms Rigney’s complex psychopathology caused a mental impairment; it includes a mental impairment, namely, treatment-resistant schizophrenia as well as possibly PTSD. This again appears to reveal a fundamental misunderstanding of the s 269C test. 492 Prof Morris, like Prof Coyle, concluded that at the time of the stabbing, Ms Rigney’s difficult-to-treat psychotic condition of treatment-resistant schizophrenia, as well as chronic PTSD (secondary to developmental trauma and child sexual abuse) and borderline personality traits, exacerbated by substance use, would have rendered Ms Rigney psychotic, thought disordered, impulsive, irrational, and unable to control her behaviour. He concluded, “based on the fact that she was so profoundly unwell”, that she did not know her conduct was wrong. Prof Morris similarly relied on the severity of Ms Rigney’s mental impairment to support his conclusion that Ms Rigney was completely unable to control her conduct, as distinct from having some capacity to control it. He said he also took the frenzied nature of the stabbing into account in arriving at his opinion. 493 Prof Morris considered that the conjoint operation of PTSD and schizophrenia explains Ms Rigney’s memory difficulties around the time of the stabbing. 494 At this stage, it is convenient to deal with the issue of Ms Rigney’s memory and the suggestion of dissociative amnesia. The evidence of Prof Coyle and Prof Morris on these topics relies to a great extent on the statistical likelihood of Ms Rigney experiencing dissociative amnesia given her mental impairment, including possibly PTSD, in combination with her history of being sexually abused as a child. 495 I note the assertion that Ms Rigney has dissociative amnesia is speculative; the evidence does not permit me to make a finding regarding Ms Rigney’s memory of the stabbing. The prosecution’s submissions in reliance on Ramsay v Watson, and the issue of whether Ms Rigney had comorbid PTSD at the time of the stabbing, can therefore be set aside. 496 The evidence also does not permit me to make a finding in respect of any brain damage suffered by Ms Rigney consequent upon child sexual abuse, or the consequences of any such damage. I note that in addition to the uncertainty as to whether child sexual abuse causes brain damage, there is simply no evidence of any brain damage being suffered by Ms Rigney. 497 Even were I able to make a finding that Ms Rigney experienced dissociative amnesia, it does not necessarily follow from such a finding that Ms Rigney -- 111 of 114 -- [2025] SASC 80 Bampton J 110 satisfied either s 269C(1)(b) or (c) at the time of the stabbing. On the other hand, I need hardly remark that Ms Rigney feigning her lack of memory is not necessarily inconsistent with her having been mentally incompetent at the time of the stabbing. In the circumstances I have described, the evidence concerning dissociative amnesia does not assist in the resolution of this matter. 498 Both Prof Coyle and Prof Morris proffer opinions that by reason of the severity of Ms Rigney’s mental impairment, she would have been rendered psychotic, thought disordered, impulsive, irrational, unable to control her behaviour, and therefore incompetent. In this context, for example, I refer to the comments of Prof Coyle that Ms Rigney was unable to reason about wrongfulness because “by definition, psychosis means a loss of contact with reality”. I am unable to accept the opinions of Prof Coyle and Prof Morris. 499 The difficulty with their opinions is that were I to accept them, the result would arguably be that any defendant who has a severe mental impairment and no memory of the alleged criminal conduct would have the mental incompetence defence available to them without it being necessary to specifically identify how they satisfied s 269C(1)(a), (b), or (c) in consequence of their mental impairment. 500 While the severity of the defendant’s mental impairment is, of course, a relevant matter in determining whether the s 269C test has been satisfied, this must be weighed against the possibility of the conduct having a non-psychotic motive. In this case, in the absence of cogent evidence of Ms Rigney’s symptoms and thought processes at the time of the stabbing, and in circumstances where there is a credible, non-psychotic alternative explanation for the stabbing, it is not sufficient to rely on the severity of Ms Rigney’s mental impairment in a general sense to make out the s 269C defence. 501 Although Ms Rigney appears to have been quite disorganised immediately after the stabbing, I accept Dr Furst’s opinion that this evidence is insufficient to satisfy the s 269C test. Both Dr Furst and Dr Nambiar identified a credible, non-psychotic alternative explanation for Ms Rigney’s conduct. Dr Furst noted that she had a history of buying cannabis from Maria Luis, had conflict with her in the days leading up to the stabbing, and had possibly attempted to buy or had bought cannabis from Maria Luis but had some form of disagreement with her in the course of that interaction. He said that it is likely that if such a disagreement had occurred, in her psychotic state, Ms Rigney would have been predisposed to react in a paranoid, impulsive and aggressive manner. Dr Furst concluded in such an instance that Ms Rigney would have acted on impulse and in a heightened emotional state but would nonetheless have known the wrongfulness of her behaviour. Similarly, Dr Nambiar considered that Ms Rigney’s relationship with Maria Luis, the perceived conflict between them, and the exculpatory explanation given by Ms Rigney for her attendance at the Luis house appeared to be more consistent with an impulsive episode of behaviour. -- 112 of 114 -- [2025] SASC 80 Bampton J 111 502 The defence contention that there is no plausible, non-psychotic explanation for Ms Rigney’s conduct, as there was no need for Ms Rigney to obtain cannabis from Maria Luis and therefore no need to have attacked her, as discussed above at [391], is not supported by the collateral evidence, including Ms Rigney’s self-report during the second police interview. 503 I accept the evidence of Dr Nambiar, Dr Ferris and Dr Furst regarding the application of the s 269C test and the need for a link between a defendant’s psychotic thought processes and the alleged criminal conduct. I also note that in Childs, it is apparent that Dr Haeney, in repeatedly and persistently interviewing the defendant, was looking for evidence that the defendant’s actions were guided or directed by psychotic phenomenology; in other words, he was looking for a link between the mental impairment and the conduct. 504 Having considered the reports and evidence of the experts, along with the collateral evidence, there is no evidence either from Ms Rigney herself or any other source proximate to or at the time of the stabbing that Ms Rigney’s actions were guided or directed by psychotic phenomenology. There is no evidence before me that the stabbing was the result of florid psychosis or a delusional belief arising from her treatment-resistant schizophrenia. However, there is evidence of a credible, non-psychotic alternative explanation for the stabbing. I accept the opinions of Dr Nambiar and Dr Furst to this effect. For the reasons I have explained, I am unable to accept Dr Ferris’ evidence regarding Ms Rigney’s competence. I prefer the evidence of Dr Nambiar and Dr Furst on the ultimate issue to that of Prof Coyle and Prof Morris, each of whom seem to start from the premise that Ms Rigney has a mental impairment and is therefore incompetent, rather than properly interrogating whether the s 269D presumption has been displaced. 505 I indicate that I have not relied on the frenzied nature of the stabbing or the number of stab wounds, given that these matters do not point to either a psychotic or non-psychotic motive for Ms Rigney’s conduct in the absence of evidence as to what precipitated the stabbing. It is also trite to point out that this Court has tried defendants charged with murder involving allegations of frenzied, non-psychotic conduct. Nor have I relied upon Ms Rigney allegedly burning clothing she was wearing at the time of the stabbing, depositing her backpack at the nearby property, and concealing a knife used in the stabbing, or the manner in which she departed Maria Luis’ home after the stabbing. Even were each of these matters proved, I am not satisfied they necessarily demonstrate that Ms Rigney had the presence of mind to distance herself from the stabbing as contended by the prosecution. Conclusion 506 It has not been established on the balance of probabilities that at the time of the stabbing, Ms Rigney did not know that her conduct was wrong; that is, that she was completely incapable of reasoning about whether the conduct, as perceived by -- 113 of 114 -- [2025] SASC 80 Bampton J 112 reasonable people, was wrong. It has also not been established that she was totally unable to control her conduct. 507 Pursuant to s 269G B(3), I am not satisfied it has been established, on the balance of probabilities, that Ms Rigney was, at the time of the stabbing, mentally incompetent to commit the offence of murder. 508 Pursuant to s 269G B(3)(b), I record a finding that the presumption of mental competence has not been displaced and order that the trial is to proceed in the normal way. -- 114 of 114 --