FORTH -v- THE STATE OF WESTERN AUSTRALIA [2026] WASCA 109
[2026] WASCA 109
Page 1
JURISDICTION : SUPREME COURT OF WESTERN AUSTRALIA
TITLE OF COURT : THE COURT OF APPEAL (WA)
CITATION : FORTH -v- THE STATE OF WESTERN
AUSTRALIA [2026] WASCA 109
CORAM : THOMSON P
MITCHELL JA
VAUGHAN JA
HEARD : 20 JULY 2026
DELIVERED : 6 AUGUST 2026
FILE NO/S : CACR 88 of 2025
BETWEEN : MITCHELL COLIN FORTH
Appellant
AND
THE STATE OF WESTERN AUSTRALIA
Respondent
ON APPEAL FROM:
Jurisdiction : SUPREME COURT OF WESTERN AUSTRALIA
Coram : QUINLAN CJ
File Number : INS 14 of 2023
Catchwords:
Criminal law - Sentencing - Whether sentence was manifestly excessive -
Culpability where person sentenced for manslaughter as the probable
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consequence of pursuing a common unlawful purpose of chasing children, and
terrorising and potentially attacking them, while one of the men was armed with
a weapon - Where the appellant was not present when a child was unlawfully
killed, but did not resile from common unlawful purpose - Sentence of 9 years'
imprisonment for manslaughter not manifestly excessive
Legislation:
Criminal Code (WA), s 8
Result:
Leave to appeal granted
Appeal dismissed
Category: B
Representation:
Counsel:
Appellant : A G Elliott & A F Kraus
Respondent : K C Cook
Solicitors:
Appellant : Aidan Kraus
Respondent : Director of Public Prosecutions (WA)
Case(s) referred to in decision(s):
Francis v The State of Western Australia [2019] WASCA 43
Hishmeh v The State of Western Australia [2012] WASCA 183
Hodges v The State of Western Australia [2025] WASCA 136
Hutton v The State of Western Australia [2022] WASCA 133
Kabambi v The State of Western Australia [2019] WASCA 44
R v Broadby [2025] QCA 55
R v Oram; R v Hinds [2022] QCA 244
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[2026] WASCA 109
JUDGMENT OF THE COURT
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JUDGMENT OF THE COURT:
Overview
1 This appeal concerns the appropriate sentence where the appellant
formed a common intention with two other men to prosecute the
unlawful purpose of chasing children, and terrorising and potentially
attacking them, while one of the men was armed with a weapon. In the
prosecution of that unlawful purpose, a child was unlawfully killed by
one of the other men. That offence was of such a nature that its
commission was a probable consequence of the prosecution of that
unlawful purpose. The appellant did not actually do any of the acts
which killed the child but nevertheless maintained the common
intention to prosecute the unlawful purpose at the time the child was
unlawfully killed.
2 The deceased child was Cassius Turvey, who was unlawfully
killed on 13 October 2022 while walking about after school. He was
15 years old. The three men involved in his death were Jack Steven
James Brearley, Brodie Lee Palmer and the appellant. Mr Brearley and
Mr Palmer were convicted of murdering Cassius Turvey, while the
appellant was convicted of manslaughter.
3 The three men chased a group of children, who were walking
about after school in the afternoon. Cassius Turvey was one of them.
He ran into some bushland, followed by Mr Brearley and Mr Palmer.
Mr Brearley struck him on the head with a pole he was carrying, and
Cassius Turvey fell over. Mr Brearley struck him on the head with the
pole more than once while he was lying on the ground. Mr Palmer was
close to, or present with, Mr Brearley when this occurred.1 The
appellant, however, did not follow the group into the bushland, but ran
towards a nearby street. He was seen yelling out 'get him', encouraging
the chase. He later celebrated with Mr Brearley and Mr Palmer about
what had occurred.2
4 The appellant was convicted of manslaughter upon the basis of s 8
of the Criminal Code (WA). He formed a common intention with
Mr Brearley to prosecute the unlawful purpose of chasing the children,
and terrorising and potentially attacking them, while Mr Brearley was
armed with a weapon.3 The unlawful killing of Cassius Turvey by
1 The State of Western Australia v Brearley [2025] WASCSR 21 (Quinlan CJ) (SR) [129] - [132].
2 SR [303].
3 SR [149].
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JUDGMENT OF THE COURT
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Mr Brearley was an offence of such a nature that its commission was a
probable consequence of the prosecution of that purpose.
5 Mr Brearley and Mr Palmer were convicted of murder.
Consistently with the jury's verdicts, the trial judge (Quinlan CJ) found
that Mr Brearley and Mr Palmer formed a common intention to chase
the boys into the bush, attack them and to cause them serious harm.4
By contrast, the trial judge found that the appellant did not join in a
common purpose to cause serious harm to the children.5 The
appellant's conviction of manslaughter, rather than murder, is
explicable on the basis that the jury were not satisfied, beyond
reasonable doubt, that the unlawful killing of a child by a person
intending to cause an objectively life-threatening injury was an offence
of such a nature that its commission was a probable consequence of the
prosecution of the unlawful purpose in which the appellant joined.
6 For the offence of manslaughter, the appellant was sentenced to
imprisonment for 9 years, reduced from 10 years for reasons of totality
relating to other offences which occurred at about the same time. The
total effective sentence imposed on the appellant for all offences was
12 years' imprisonment. Mr Brearley and Mr Palmer were sentenced to
life imprisonment for the murder of Cassius Turvey, with minimum
non-parole periods of 22 years (Brearley) and 18 years (Palmer).
7 The appellant has appealed against his sentence on one ground
only, asserting that the length of his term of imprisonment for the
offence of manslaughter is manifestly excessive. The gravamen of the
appellant's argument is that, because he was not present when Cassius
Turvey was killed, and because his actions did not directly increase the
probability of Cassius Turvey being unlawfully killed, a sentence of
9 years' imprisonment goes well beyond a sentence which is
proportionate to his culpability.
8 In essence, the appeal depends upon whether it was open to the
trial judge to regard 9 years' imprisonment (reduced from 10 years for
totality) as commensurate with the seriousness of the manslaughter
offence. That is, the critical issue is whether the sentence imposed for
the manslaughter offence was unreasonable or plainly unjust so that
sentencing error is to be inferred from the outcome. If the
manslaughter sentence is upheld, there is no challenge to the 12-year
total effective sentence.
4 SR [116].
5 SR [149], [316].
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JUDGMENT OF THE COURT
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9 To properly consider the appeal, it is necessary to set out, in a
detailed way, the factual basis on which the trial judge sentenced the
appellant. This requires an understanding of the events leading up to
the death of Cassius Turvey. These events commenced on 9 October
2022, although Cassius Turvey had no part in the events until
13 October 2022. The earlier events provide important context for the
sentence imposed upon the appellant for the manslaughter of Cassius
Turvey, and explain why the sentence for that offence was reduced
from 10 years to 9 years on account of considerations of totality.
Detailed facts
10 On appeal, there is no dispute about the relevant facts. The trial
judge made comprehensive and detailed factual findings for the purpose
of sentencing. None of these have been challenged on this appeal.
11 At the relevant time, Mr Brearley was living with his partner
Aleesha Louise Gilmore at the home of Ms Gilmore's father.6
Mr Brearley was a casual bricklayer, who also sold and supplied
cannabis on the side.7 Ms Gilmore was a childcare worker.8
Mr Brearley was 21 years old, while Ms Gilmore was 20 years old.9
Ms Gilmore had a younger brother, Cody. He was 14 years old.
12 Mr Palmer was acquainted with Mr Brearley, by reason that
Mr Palmer grew cannabis which he supplied to Mr Brearley.10
Mr Palmer was 27 years old at this time.
Count 1: Aggravated unlawful detention of Seth Flinn
13 On the afternoon of 9 October 2022, Cody arranged to have a fight
with the former boyfriend of his current girlfriend. However, when
Cody turned up to the arranged site, more boys turned up than he
expected. He called Ms Gilmore, saying that he was going to be
'mobbed'.11
14 Ms Gilmore was at home with Mr Brearley. The appellant and a
fourth person, Ethan Robert Mackenzie, were with her. Mr Mackenzie
was 18 years old. All four of them immediately drove to the area where
the fight was supposed to occur, and picked up Cody and Cody's
6 SR [14].
7 SR [16].
8 SR [17].
9 SR [15].
10 SR [19].
11 SR [25].
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friend.12 They were in a Kia Rio owned and driven by Mr Brearley.
They were driving around the area when they encountered a 14 year
boy, Seth Flinn,13 walking along. Cody and his friend were seated in
the car, wearing balaclavas.14
15 Both Ms Gilmore and Mr Mackenzie got out of the car.
Ms Gilmore ordered Seth Flinn to get into the car, while Mr Mackenzie
was holding up a 30 cm knife in a black sheath (with the tip sticking
out). Seth Flinn was scared of the knife, so he got into the car. He was
kept in the car during further events recorded below, and then taken to
Ms Gilmore's house. He remained there for an hour or so before he
was finally taken home.15
16 This incident led to the appellant, Ms Gilmore, Mr Mackenzie and
Mr Brearley all being convicted of aggravated unlawful detention
relating to Seth Flinn.
Count 2: Assault of Lucas Sheean occasioning bodily harm
17 After the group had picked up Seth Flinn, Mr Brearley continued
to drive around the area, searching for the group which was supposed to
have come to 'mob' Cody. Eventually, another group of boys came into
sight. Apparently, they had come to the area for an entirely different
fight. Nevertheless, Mr Brearley, Mr Mackenzie and the appellant
jumped out of the car and started yelling at them and chasing them.
Mr Brearley, Mr Mackenzie and the appellant chased one of them,
Lucas Sheean.16 He was 15 years old at the time. The trial judge
described him as a 'small kid'.17
18 Mr Brearley, Mr Mackenzie and the appellant attacked Lucas
Sheean. Mr Brearley punched him in the head. After that, Lucas
Sheean went down, and the three assailants hit or kicked him.
Mr Mackenzie poked him with the knife he was carrying, with the
unprotected knife tip. Lucas Sheean suffered a small cut towards the
bottom of his ribcage, which was about 1 cm long and 2 mm deep. It
started to bleed, and later became infected for several days.18
12 SR [22] - [26].
13 A pseudonym.
14 SR [29].
15 SR [30] - [32].
16 A pseudonym.
17 SR [36] - [41].
18 SR [42] - [45].
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19 Each of Mr Brearley, Mr Mackenzie and the appellant were
convicted of assault occasioning bodily harm arising from this attack
upon Lucas Sheean. Mr Mackenzie's act of poking Lucas Sheean with
the knife and causing bodily harm constituted the offence charged in
count 2 on the indictment. Mr Brearley and the appellant were held
equally guilty, having intentionally aided in the commission of the
offence.19
Count 3: Aggravated unlawful detention of Lucas Sheean
20 After the assault upon Lucas Sheean, Mr Brearley dragged Lucas
Sheean towards the car, with the aid and encouragement of the
appellant and Mr Mackenzie. Ms Gilmore had by now taken over
driving the car.20 Mr Brearley frog-marched him towards the car.
Mr Brearley and the appellant both made serious threats of bodily harm
to Lucas Sheean while dragging him to the car. As well, they removed
his shoes, to make it more difficult for him to run away, and smashed
his mobile phone. By the time he reached the car, his shirt had been
torn off, and he was bleeding. When he reached the car, he was forced
into it.21
21 At this stage, Ms Gilmore looked at Lucas Sheean and asked what
his assailants had been doing to 'the poor kid'.22 As well, Cody and his
friend in the car recognised Lucas Sheean, and it became clear that he
had nothing to do whatsoever in relation to 'mobbing' Cody.23
Nevertheless, Lucas Sheean was taken back to Ms Gilmore's home
along with Seth Flinn. Lucas Sheean had a shower there, and was
given some clothes and a Nintendo Switch. He said that they 'all sort of
apologised'. Both Lucas Sheean and Seth Flinn were then driven home.
However, as Lucas Sheean was dropped off, Mr Brearley and the
appellant told him not to say anything or they would hurt him.24
22 Mr Brearley, Mr Mackenzie, the appellant and Ms Gilmore were
convicted of aggravated unlawful detention due to what occurred to
Lucas Sheean.
19 SR [46] - [47].
20 SR [48].
21 SR [49] - [52].
22 SR [56].
23 SR [56].
24 SR [59] - [62].
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Events of 12 October 2022
23 On 12 October 2022, at around 4.00 pm, a group of school-aged
children went to Ms Gilmore's house and broke a number of windows
on Mr Brearley's Kia Rio, which was parked outside. The trial judge
found that there was no suggestion that the culprits responsible for this
included Seth Flinn or Lucas Sheean. Further, the trial judge found that
there was nothing to suggest that the group of school children attacked
by Mr Brearley and the appellant on the following day (ie 13 October
2022) had anything to do with the smashed car windows.25
24 At some point, Mr Brearley thought that a child he had seen riding
a bike around the neighbourhood was responsible for the smashed
windows. The child's mother worked at the same early learning centre
as Ms Gilmore. Mr Brearley went to this early learning centre and
demanded that the child's mother pay for his broken windows. This
caused an altercation between the child's mother and Ms Gilmore,
which led to Ms Gilmore losing her job at the early learning centre.26
Events of 13 October 2022 - Prelude to offending
25 Mr Brearley, the appellant and Ms Gilmore were at Ms Gilmore's
house around midday on 13 October 2022.27 Mr Palmer joined the
group just before 1.00 pm.28 Mr Brearley, Mr Palmer, the appellant and
Ms Gilmore then travelled to Mr Palmer's house, which was some
distance away. They arrived at 1.48 pm.29 They remained there
drinking and talking until 2.36 pm. At that point, Cody rang
Ms Gilmore and said that he was being threatened with a fight or a
'run-through'. While the trial judge was satisfied that there had been an
arranged fight, his Honour found that there was no evidence that there
was ever a threatened 'run-through'. He said that this could just as
easily have been made up by Cody to try and get Mr Brearley,
Mr Palmer, the appellant and Ms Gilmore involved.30
26 Before they all left Mr Palmer's house, Mr Palmer picked up some
knuckledusters, which he showed to the appellant.31 They drove back
to Ms Gilmore's house, where there was a group of boys, including
Cody. They arrived at 3.07 pm, and started preparing for a fight. There
25 SR [64] - [66].
26 SR [67].
27 SR [71].
28 SR [72].
29 SR [78].
30 SR [79] - [80].
31 SR [81].
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were discussions about whether they had their 'dusters' and whether
they were ready for a fight. Mr Brearley and the appellant went into an
alleyway next door to this house, and used an axe to break poles off
some trolleys, to use as weapons.32
27 At 3.22 pm, Mr Palmer and the appellant drove to a nearby oval,
looking for some particular individuals, who might have been planning
a fight with Cody. At 3.26 pm, Mr Palmer and the appellant returned to
the home, and picked up Mr Brearley. Mr Brearley said that somebody
had smashed up his car, and that 'they're about to die'. The trial judge
accepted that Mr Brearley was not expressing an intention to actually
kill someone at this point, but inferred that Mr Brearley was still clearly
angry about his car windows having been broken, and that he was
determined to get some sort of revenge. The trial judge concluded that
the car windows were a large part of Mr Brearley's motivation for the
actions that followed on that afternoon.33
28 The car returned to Ms Gilmore's house at 3.37 pm, and left once
more at 3.46 pm. Mr Palmer, Mr Brearley, the appellant and
Ms Gilmore were in the car when it left. As well, they took at least two
trolley poles as weapons, and Mr Palmer had his knuckledusters.34
29 At around the same time, a group of children from Swan View
Senior High School and Governor Stirling Senior High School arrived
at the Midland Train Station. This group included Cassius Turvey.
There were at least 17 others in that group.35 The trial judge found that
no-one in this group had had anything whatsoever to do with the
damage to Mr Brearley's car, or with any threatened 'run-through' of his
house.36
30 The group of school children got onto a bus, and travelled a short
distance, where they all got off the bus. They were going to see an
organised fight.37 The car with Mr Brearley, Mr Palmer, the appellant
and Ms Gilmore drove past the group of school children. Ms Gilmore
yelled at the group. However, the trial judge found that her primary
concern was with preventing a fight with Cody, not with the broken
windows of Mr Brearley's car.38
32 SR [75], [82] - [83].
33 SR [85].
34 SR [86].
35 SR [87].
36 SR [90].
37 SR [91].
38 SR [92] - [93].
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31 Mr Brearley, Mr Palmer and the appellant then became angry with
Ms Gilmore, and she left the car. Mr Palmer drove the car back to the
group of children and parked on the verge. Mr Brearley and the
appellant got out of the car, and yelled at them about the smashed
windows. Mr Palmer stayed with the car.39 Mr Brearley was armed
with a trolley pole.40 The trial judge was not satisfied beyond
reasonable doubt whether Mr Palmer or the appellant also had a trolley
pole, although there was evidence that it was likely that one of them
did.41
32 Mr Brearley took a swing at one member of the group, who
stepped forward in what appears to have been an attempt to protect
other members of the group from Mr Brearley.42
Count 4: Aggravated assault of Nick Traill occasioning bodily harm
33 After Mr Brearley had taken a swing at a member of the group,
some of them ran off. He then turned towards a 13 year old boy on
crutches, who was standing with two girls. Mr Brearley hit this boy,
Nick Traill,43 in the face with the trolley pole he was carrying. This
caused Nick Traill to stumble backwards and lose his crutches and hat.
Nick Traill suffered bruising to his face and a sore nose for about a
week after the attack.44
34 Mr Palmer, the appellant and Ms Gilmore were also guilty of this
offence. The assault upon Nick Traill was the probable consequence of
the common intention to prosecute the unlawful purpose of threatening
children with weapons.45
Count 5: Stealing
35 The appellant took Nick Traill's crutches and hat and put them in
the tray of Mr Palmer's car. The appellant admitted this in his record of
interview. This constituted the offence of stealing charged in count 5
on the indictment, in respect of which the appellant pleaded guilty on
2 December 2024. Mr Palmer was also convicted of this charge, but
not Mr Brearley. Mr Brearley had run off into a public grassed area
next to where the incident with Nick Traill occurred by the time the
39 SR [96].
40 SR [97].
41 SR [98].
42 SR [100].
43 A pseudonym.
44 SR [101] - [102].
45 SR [105].
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appellant took the items. Mr Brearley was chasing other children
across this field.46 He was unaware of the theft.
Count 6: Unlawful killing of Cassius Turvey
36 After the assault upon Nick Traill, there no longer remained any
basis to say that the attacks by Mr Palmer, Mr Brearley and the
appellant were to prevent Cody being mobbed. All of the children were
running away from the scene. The trial judge therefore found that the
purpose of Mr Palmer, Mr Brearley and the appellant in continuing the
attacks after this point was 'about revenge and terrorising a group of
kids for its own sake'.47
37 Initially, Mr Brearley chased some children across the grassed area
on foot. However, Mr Palmer drove his car onto this area, with the
appellant as a passenger. Mr Brearley got into the car. They drove
across the grassed area, and approached a creek line, where they
stopped the car. All three people got out of the car. Mr Brearley, with
Mr Palmer following, ran one way along the creek line, into bushland,
chasing some boys.48
38 The trial judge found that, at this point, Mr Brearley and
Mr Palmer shared a common intention to chase the boys into the bush,
attack them and cause them serious harm. His Honour said that the pair
of them were actively chasing the boys and were intent on violence.
His Honour found that Mr Brearley was still armed with a trolley pole,
and was intending to use it against one of the children. However, the
trial judge found that he could not be satisfied beyond reasonable doubt
that Mr Palmer was also armed with a trolley pole, although his Honour
said that Mr Palmer was 'clearly part of the common intention with
Mr Brearley to catch and seriously harm one of the boys'.49
39 The trial judge then made the following findings about the
appellant:50
You on the other hand Mr Forth, as with your conduct generally, didn't
get actively involved in the chase through the bushes. As I said earlier
Mr Forth, you liked to talk tough, but when push came to shove, you
kept in the background. And you did so again at this time. You got to
46 SR [106] - [109].
47 SR [111] - [112].
48 SR [114] - [115].
49 SR [116].
50 SR [117] - [118].
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the edge of the bushland but you didn't go through the creek but ran up
to Lloyd Street.
Nevertheless, I do find, Mr Forth, that you joined in the common
purpose of chasing and terrorising the kids. In particular, I find that it
was you who yelled out 'get him', as described by the independent
witness Ms Ali in her evidence. While Ms Ali said at one point in her
evidence that she had assumed it was the person she could see in the
tradie shirt, I am satisfied that her assumption was correct. That
behaviour was entirely consistent with your conduct generally,
Mr Forth, which, as I have said, was to talk tough but to leave the dirty
work to the others. You were not armed at the time but, I am satisfied,
were aware that Mr Brearley was armed, as he had been in possession
of a trolley pole the entire time from when he initially took it out of the
car, to when the car arrived near the creek line.
40 What happened next is that Mr Brearley chased Cassius Turvey
across the creek. While Cassius Turvey was running away from
Mr Brearley, Mr Brearley hit him on the side of his head with the
trolley pole. Cassius Turvey fell to the ground as a consequence of this
blow. The trial judge found that Mr Brearley continued to swing the
pole with his arms above his head, and forcefully bring it down hitting
Cassius Turvey's head. The trial judge accepted that Mr Brearley hit
Cassius Turvey multiple times. The injuries to Cassius Turvey
indicated that he was hit at least twice in the head. The trial judge
found that Mr Brearley struck Cassius Turvey more than twice, but he
could not be satisfied beyond reasonable doubt how many times. The
trial judge found that Mr Brearley was in an uncontrolled rage, and
yelling at Cassius Turvey, while Cassius Turvey was yelling and crying
and asking Mr Brearley to stop.51
41 At around this point Mr Palmer arrived at the scene, and
interrupted Mr Brearley. He said to him, 'stop, that's enough'. He tried
to pull Mr Brearley away from Cassius Turvey.52 The trial judge was
not satisfied beyond reasonable doubt that Mr Palmer had physically
joined in the attack on Cassius Turvey.53 The trial judge then said:54
That is not to say that the attack on Cassius Turvey was not part of your
common intention with Mr Brearley, Mr Palmer. As I have said, I am
satisfied that the two of you shared a common intention to catch any of
the boys you could, assault them and do them serious harm. It is just
that, when you arrived, to use your words Mr Palmer, Mr Brearley had
51 SR [121], [128] - [130].
52 SR [131] - [132].
53 SR [133].
54 SR [134].
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done 'enough'. Indeed, I accept that Mr Brearley went further in his
violence and rage than even you expected Mr Palmer. That, of course,
provides you with no excuse. The law provides that once you embark
on the kind of dangerous and violent unlawful purpose that you and
Mr Brearley embarked upon, Mr Palmer, you are liable for the probable
consequences of it, and you can't be heard to complain when one of
your co-offenders goes even further than you predicted.
42 The trial judge found that Mr Brearley did not intend to kill
Cassius Turvey, but said that he was satisfied that 'in your rage you
didn't care, and didn't spare a single thought for the likelihood that what
you were doing would kill him'.55 The trial judge also found that
Mr Brearley intended to cause serious blunt force injury to Cassius
Turvey's head, of such a nature that it was objectively likely to cause
his death. The blows inflicted by Mr Brearley split Cassius Turvey's
right ear completely in half, and caused a long straight wound across
his forehead near his hairline. Internally, Cassius Turvey had a
subdural haematoma on the righthand side of his head and an
intraparenchymal haematoma to the righthand side of his brain. While
Cassius Turvey was discharged from hospital for a short period of time,
his brain injury worsened and he died at 5.10 pm on 23 October 2022.56
43 In relation to Mr Palmer, the trial judge said:57
As I have found, you were not the person who killed Cassius Turvey,
but you are equally guilty on the basis that you shared a common
intention with Mr Brearley to prosecute the unlawful purpose of chasing
the boys into the bush, attacking them and causing them serious harm.
It was a probable consequence of the prosecution of that unlawful
purpose that an offence in the nature of murder would be committed;
namely that someone would be killed by one of you with the intention
to cause an objectively life threatening injury.
44 The trial judge then addressed the appellant's position, and said:58
You shared a common intention with Mr Brearley to prosecute the
unlawful purpose of chasing the boys into the bush, terrorising and
potentially attacking them, but I accept that you didn't share the
common intention to do them serious harm. Indeed, consistent with
what I have already said about your involvement in all of the events in
this case, you gave little thought at all to the consequences of your
actions, and were just following along in the excitement of trying to be
a tough guy. Indeed, as I will come to, while you are starting to do so,
55 SR [136].
56 SR [136] - [137].
57 SR [146].
58 SR [149].
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you are still yet to fully appreciate the seriousness of your conduct that
day. But, on the day, your actions were even more thoughtless. Given
that Mr Brearley was, to your knowledge, armed, it was clearly a
probable consequence of the unlawful purpose that you shared with
Mr Brearley that someone may be unlawfully killed, hence your
conviction for manslaughter, although it could not be concluded,
beyond reasonable doubt, that the unlawful purpose that you shared in
common with Mr Brearley had as a probable consequence that someone
would be killed by one of you with the intention to cause an objectively
life threatening injury.
45 The trial judge made a particular point of finding that Cassius
Turvey was 'completely and utterly innocent of any wrongdoing
whatsoever'.59 The trial judge found that the only reason he was the
person killed was that he was the person who happened to be caught.60
Aggravating factors
46 The trial judge considered that there were a number of common
aggravating factors which applied to the offending which had occurred,
including the unlawful killing of Cassius Turvey. In summary, these
were:
(a) the victim of every offence was a child who was, by nature, a
vulnerable victim;61
(b) all of the offences were committed by groups of adults acting
together. This was particularly serious given that there were
multiple adults offending against vulnerable children;62
(c) all of the offences, including the unlawful killing of Cassius
Turvey, were committed as part of vigilante activity. The trial
judge identified the particular vice in such activity. He said that
vigilante violence involves individuals purporting to take the
law into their own hands by harming perceived wrongdoers.
Such conduct is not only an attack upon the victims, but also an
attack upon the rule of law, which requires that members of the
community resolve their differences by lawful means rather
than personal vengeance. It was even worse that the vigilante
59 SR [122].
60 SR [122].
61 SR [153] - [154].
62 SR [155].
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activity in this case was directed against completely innocent
children;63 and
(d) the use of weapons in the offences involving assault
occasioning bodily harm and in killing Cassius Turvey.64
47 The trial judge also identified the following aggravating factors
related specifically to the unlawful killing of Cassius Turvey:
(a) the prosecutor did not allege, and the trial judge did not find,
that the crimes were racially motivated.65 However, the attack
by a group of non-Aboriginal men upon a group of
predominantly Aboriginal children, using racial slurs and
racially charged language, created a legitimate fear and sense of
threat within the Aboriginal community that the attack was
racially motivated;66
(b) the offenders exhibited glee and celebrated their offending. In
particular, only hours after the attack, the appellant and
Mr Palmer participated in a video recording, where they waved
their hands in gangster-like gestures and proclaimed, among
other things, that 'We got 'em all';67 and
(c) the offenders disposed of the evidence to conceal their crime.
They disposed of the trolley poles and Nick Traill's crutches and
hat. It appears that it was Mr Palmer who was responsible for
disposing of the items belonging to Nick Traill.68
Victim impact
48 The trial judge considered the impact of the various offences upon
their victims. In relation to the unlawful killing of Cassius Turvey, he
accepted that there was a wide 'blast radius' of people who were
adversely affected by his brutal death, ranging 'from the children who
were terrorised and watched their friend beaten to death, to their
families and friends and to the community as a whole'.69
63 SR [156] - [157].
64 SR [158].
65 SR [7].
66 SR [162].
67 SR [164].
68 SR [165].
69 SR [169].
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49 The trial judge also took account of the statement made by
Mechelle Turvey, who was the mother of Cassius Turvey. She said:70
There are no words that can fully capture the devastation of losing
someone you love to violence. Cassius was not just a part of my life, he
was my future, my family, my home. The day he was taken from us is
the day my world shattered.
He was murdered. That truth is something I live with every single day.
It's not just the absence of his presence, it's the silence where his
laughter used to be, the emptiness in moments we were supposed to
share, and the unbearable weight of knowing he didn't get to live the
life he deserved.
The trauma of his death is something I carry every day. I will never see
him grow older, never hear his voice again, never feel the comfort of
his embrace. The pain is constant, and the grief is immeasurable.
What was taken from me was not just a person, but a lifetime of
memories we were meant to create. I live with the ache of what could
have been, and the injustice of what was stolen.
Appellant's personal circumstances and mitigating matters
50 The trial judge took into account the following personal
circumstances of the appellant in sentencing him:
(a) the appellant was 24 years old at the time of offending, and was
27 years old at the time of sentencing;71
(b) the appellant was born in Western Australia, and has one older
sister. He had a happy and healthy early childhood, but his
parents separated amicably when he was 9 years old. Although
the appellant initially lived with his father, during his teenage
years he lived alternatively with both parents at different
times;72
(c) the appellant attended school until the end of year 12. He was
diagnosed with ADHD and dyslexia as a child. He had
difficulty reading;73
(d) the appellant started smoking cannabis when he was 13 years
old, and was expelled from one school in year 10 for smoking
70 SR [175].
71 SR [282].
72 SR [284].
73 SR [287].
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cannabis on a school bus. He claimed to have stopped using
cannabis 6 months before October 2022, subject to an
occasional lapse after the offences were committed;74
(e) the appellant maintained steady employment since high school,
commencing a number of different apprenticeships although
never finishing one of these. He had worked for most of his
adult life for his father, for about seven years;75
(f) the appellant had no significant criminal record, apart from
minor offending as a child for which he received spent
convictions. The trial judge considered that the appellant
should be treated as of good prior character for the purposes of
sentencing;76
(g) the court had received character references from family and
friends of the appellant which accepted the jury's verdict of
manslaughter; acknowledged the pain which the offending had
caused, particularly to the family of Cassius Turvey; and which
vividly demonstrated that the appellant had a loving and
supportive family that were working towards the appellant's
rehabilitation.77
51 The trial judge considered that the following matters were
mitigating circumstances which he should take into account in
sentencing the appellant for manslaughter:
(a) the appellant's youth at the time of offending, although this was
not a significant mitigating factor at the age of 24 years old. He
was on the cusp of the point when age would no longer be a
mitigating factor;78
(b) the appellant's remorse, although having regard to the plea of
not guilty this could only be regarded as commencing to
develop in its early stages, as the appellant began to appreciate
the gravity of what he had done;79
(c) the appellant's good prospects of rehabilitation, if he could truly
accept that he was actually responsible for the death of Cassius
74 SR [287] - [288].
75 SR [289].
76 SR [291].
77 SR [292] - [296].
78 SR [299].
79 SR [300] - [304].
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Turvey, and having regard to the many people around him who
were prepared to support him.80
Other matters
52 In sentencing the appellant (and the other offenders), the trial
judge specifically reminded himself of the parity principle, and the need
to ensure consistency in sentencing co-offenders.81 He also took into
account, as a mitigating matter, that the way in which the trial had been
conducted involved a number of important concessions and admissions,
which avoided the need for detailed and potentially distressing evidence
(such as evidence about the final days of Cassius Turvey).82
53 The trial judge also took into account the prison conditions in
which the appellant and his co-offenders had been remanded. He
acknowledged that these were 'sub-optimal', and that as the offenders
were on remand, they were unable to participate in targeted
rehabilitation programs. The trial judge also acknowledged that the
appellant and the other offenders had required special custodial
arrangements, given the notoriety of their crimes.83
54 The trial judge also identified that the statutory penalty for
manslaughter is a maximum term of life imprisonment.84 He correctly
recognised that there is no tariff for manslaughter offences. He said:85
In relation to all those offences, there [is] no tariff, which means that
there is no automatic sentence that applies. Offences like unlawful
detention, assault occasioning bodily harm and manslaughter can cover
a very wide range of conduct and it can be very difficult to compare one
case to another, because the circumstances differ so much. For
example, there is a big difference between an unlawful detention that
takes place for minutes or hours and one that takes place for days,
weeks or even months. Likewise, there is a difference between a
manslaughter where the person doesn't intend to do any harm and a
manslaughter where the person does intend to do harm. What I am
required to do is determine, as far as possible, where your particular
offences stand in the scale of seriousness, in light of all of the
circumstances, and of course, I am also required to take into account
your personal circumstances.
80 SR [304] - [305].
81 SR [183].
82 SR [186].
83 SR [187].
84 SR [178].
85 SR [179].
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Reasons for manslaughter sentence
55 In the circumstances of the matters set out above, the trial judge's
reasons for imposing a sentence of 10 years' imprisonment on the
appellant for the manslaughter offence were as follows:86
Your conviction for the manslaughter of Cassius Turvey is obviously
the most serious of the offences for which I must sentence you.
Of course, when assessing the extent of your culpability it is relevant
that you did not directly kill Cassius Turvey, or indeed physically attack
him or any of the other boys at all on 13 October 2022. While you are
legally responsible for Cassius' death, your culpability is not as great as
it would be if you had been responsible for the lethal blows inflicted on
him.
Your conviction for manslaughter, rather than murder, also necessarily
means, I find, that you did not have an intention to do any of the
children serious harm. As I have said you gave little thought at all to
the consequences of your actions, and were just following along with
the others in the excitement of trying to be a tough guy. Nevertheless,
general deterrence requires that thoughtless, casual violence be
denounced, just as it requires that vigilante behaviour be condemned in
the strongest possible terms.
In your case, Mr Forth, in my view personal deterrence is a less
significant sentencing consideration. As I have said, you are beginning
to understand and to accept your responsibility for Cassius Turvey's
death and there is good reason for optimism that the support of those
around you, which I accept to be genuine and sincere, will enable you
to continue on that path. That leads me to conclude that you have good
prospects of rehabilitation, and the prospect of you reoffending is low.
Nevertheless, these matters, while of real weight, cannot eclipse the
great harm wrought by the death of a child and the need for the law to
punish those responsible. I have dealt with the aggravating factors
earlier and most of them, as I identified them, apply to you. Your prior
good character and your good prospects reduce the sentence that I
would otherwise impose, but it must nevertheless be substantial.
In all of the circumstances, and taking into account all relevant
considerations, in my view, the appropriate sentence for your
conviction for manslaughter is 10 years imprisonment.
56 The trial judge then considered questions of totality, having regard
to the fact that he was also sentencing the appellant for the other five
offences referred to above. He said that objectives of sentencing should
86 SR [314] - [319].
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not crush the appellant's newfound commitment to rehabilitation.87
However, he also said that the appellant had been convicted of multiple
offences on separate days, which required there to be some
accumulation of the sentences for these offences.88 He then said:89
In my view the total effective sentence that properly reflects the overall
criminality of all of the offences you have committed is one of 12 years
imprisonment. In all of the circumstances that is best reflected, in my
view, [by] reducing your sentence on count 6 to 9 years for reasons of
totality and by ordering that your sentences for your convictions of
aggravated unlawful detention be served cumulatively on your sentence
for manslaughter and on each other. As I have said, with the other
sentences being served concurrently, that produces a total effective
sentence of 12 years imprisonment.
Appeal ground
57 The single ground of appeal is that:
The learned judge erred in imposing a sentence in relation to count (6),
namely the offence of manslaughter, that was manifestly excessive as to
length.
Legal principles - manifestly excessive sentence
58 The appellant accepts90 that the appeal ground is to be determined
by applying the following principles stated in Kabambi v The State of
Western Australia, which govern appeals in which error is inferred
upon the basis that an individual sentence is manifestly excessive:91
(1) Sentencing is a discretionary exercise. An appellate court can
intervene only if the appellant demonstrates either an express or
implied material error. Express error involves acting on a wrong
principle, for example by mistaking the law or facts or taking
into account an irrelevant matter. Implied error arises where the
end result is so unreasonable or unjust that the court must
conclude that a substantial wrong has occurred. Thus, an
appellate court cannot substitute its own opinion for that of the
sentencing court merely because the appellate court would have
exercised a sentencing discretion differently.
(2) In order to determine whether a sentence for an individual
offence is manifestly excessive or inadequate, the offence
should be viewed in light of the maximum sentence prescribed
87 SR [321].
88 SR [322].
89 SR [322].
90 WAB 21 (appellant's submissions [73]).
91 Kabambi v The State of Western Australia [2019] WASCA 44 [21].
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by law for the crime, the standards of sentencing customarily
imposed with respect to it, the place that the criminal conduct
occupies in the scale of seriousness of crimes of that type, and
the offender's personal circumstances.
Gravamen of the appellant's argument
59 The appellant conveniently summarised the essential basis of his
challenge in his written submissions, in the following way:92
The argument as to manifest excess is as follows:
a) Mr Forth was liable for manslaughter by section 8 of the
Criminal Code, and not on the basis that he knowingly assisted
or encouraged in a homicide.
b) Mr Forth did not share an intention to seriously harm the
children, did not possess a weapon, and that he did not attack
children himself. This was expressed by his Honour at sentence.
c) Mr Forth's actions did not materially or substantially advance
the commonly intended unlawful purpose that he shared with
Mr Brearley.
d) Because Mr Forth did not materially advance the commonly
intended unlawful purpose he did not substantially increase the
probability of the offence occurring. He is therefore less
culpable than a member of the intended unlawful purpose that
did substantially increase the probability.
e) Mr Forth was separate from the offence that was a probable
consequence of the purpose he shared with Mr Brearley.
Mr Forth did not perceive an assault on a prone child taking
place and did not knowingly assist it.
f) Mr Forth's culpability should be viewed as being towards the
lower end, higher than a person beginning to withdraw from a
common unlawful purpose but distant from a person that
physically and/or knowingly affected Cassius Turvey by
violence and/or near presence.
g) Because of a) through f), and taking into account Mr Forth's
personal circumstances and other sentences imposed in respect
of manslaughter, the sentence imposed as to count 6 was
manifestly excessive.
92 WAB 23 - 24 (appellant's submissions [85]).
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60 In substance, the fulcrum of this argument is that the appellant's
culpability is much lower than warrants a sentence of 9 years'
imprisonment.
61 In paragraph (g) of the summary of the argument, the appellant
refers to other sentences imposed in respect of manslaughter. The
appellant has identified four cases in his written submissions.93
Consideration
62 This is a case where implied error is asserted. Therefore, applying
the principles from Kabambi, the question is whether the end result is
so unreasonable or unjust that the court is driven to conclude that a
substantial wrong has occurred. Whether the end result is so
unreasonable or unjust requires consideration of the maximum sentence
prescribed by law for the crime, the standards of sentencing customarily
imposed with respect to it, the place that the criminal conduct occupies
in the scale of seriousness of crimes of that type, and the offender's
personal circumstances.94
Maximum penalty
63 The maximum penalty for the offence of manslaughter is life
imprisonment. This maximum penalty demonstrates the gravity of the
offence.95
Customary sentencing standards
64 It has been said many times that there is no sentencing tariff, or
well defined range of sentences, for the offence of manslaughter, due to
the great variation of circumstances in which the offence may be
committed.96
65 Notwithstanding that, it is possible to gain general guidance about
the significance of certain matters by considering other cases. For
example, the present case involves sentencing an offender who is a
member of a group of people pursuing a common unlawful purpose,
where the offender does not himself do the acts which kill the victim.
93 R v Oram; R v Hinds [2022] QCA 244; R v Broadby [2025] QCA 55 (Broadby); Francis v The State of
Western Australia [2019] WASCA 43 (Francis); Hutton v The State of Western Australia [2022] WASCA
133 (Hutton).
94 Kabambi [21(2)].
95 Francis [49] - [51].
96 Eg Francis [54]; Hishmeh v The State of Western Australia [2012] WASCA 183 [69]; Hutton [44].
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66 In this State, the decision of Hishmeh v The State of Western
Australia97 is informative, although it was decided at a time when the
maximum penalty for manslaughter was 20 years' imprisonment, not
life imprisonment.
67 In that case, Hishmeh and another man (Johnston) entered a house
where they believed that there was a large quantity of drugs and money.
The plan was to rob the woman who resided at the house. The role of
Hishmeh was to accompany Johnston, to threaten this woman and any
other person who might be with her, to obtain the drugs and money and
to use such force as was necessary to do so. They both entered the
house. Hishmeh menaced a man who was present with the woman,
while Johnston attacked the woman. Johnston inflicted serious injuries
upon the woman, by punching her, striking her with a hammer and
violently forcing her head through the glass window of a cabinet. The
woman died as a result of the injuries inflicted upon her by Johnston.
68 After a trial of Johnston and Hishmeh, Johnston was convicted of
murder. The jury was unable to agree on a verdict in respect of the
charge of murder brought against Hishmeh. However, the State then
accepted a plea of guilty by Hishmeh to the lesser charge of
manslaughter, in full satisfaction of the charge of murder. Hishmeh
was convicted applying s 8 of the Criminal Code. Johnston's murder of
the woman was a probable consequence of the prosecution of a joint
unlawful purpose, notwithstanding that it was not Hishmeh's subjective
intention to either kill her, or to cause her bodily injury of such a nature
as to endanger or be likely to endanger her life. The trial judge
proceeded to sentence Hishmeh on the basis that he had not personally
struck or assaulted the woman who died, and that Johnston's level of
violence had been greater than Hishmeh expected.98
69 The trial judge found that the starting point for sentencing
Hishmeh was 11 years' imprisonment, but reduced this to 8 years and
6 months taking into account a 23% discount of 2 years and 6 months
for the plea of guilty.99
70 An appeal against Hishmeh's sentence on the ground that his term
of imprisonment was manifestly excessive was dismissed. Martin CJ
97 Hishmeh v The State of Western Australia [2012] WASCA 183.
98 Hishmeh [13] - [14].
99 Hishmeh [86].
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(with the agreement of Buss and Mazza JJA) relied upon the
importance of general deterrence in this type of case. He said:100
General deterrence is an important factor in sentencing for the
manslaughter committed by Mr Hishmeh. Mr Hishmeh was aware that
his co-offenders had planned to steal money or drugs from Ms Van
Dongen and that intimidation or force would be used. Mr Hishmeh
actually used intimidation and such force as was necessary to enable
Mr Johnston to steal any money or drugs which might have been at
Ms Van Dongen's house. Condign punishment is necessary and
appropriate in sentencing for an unlawful killing committed in these
circumstances, including an unlawful killing that was a probable
consequence of the prosecution of a joint unlawful purpose.
71 The similarities with the present case are that Hishmeh had joined
in a common unlawful purpose, but was not personally responsible for
the actions causing the victim's death. Moreover, Johnston's level of
violence was unexpected, and not subjectively contemplated by
Hishmeh. On the other hand, Hishmeh was present and directly
assisted in carrying out the unlawful purpose by intimidating and
detaining the man present in the house, whereas the appellant in this
case was away from the scene where Mr Brearley repeatedly struck
Cassius Turvey's head with the pole. Nevertheless, the appellant in this
case maintained the common purpose, as is evident from his call of
encouragement to 'get him' and from the celebratory video afterwards.
Moreover, the appellant here had been in the car chasing down the
group of boys, including Cassius Turvey. It may also be observed that
the present case is more serious than Hishmeh, in that this case
involves adult men chasing down children walking about after school in
the afternoon, with the intention of terrorising and potentially attacking
them. In, and as a probable consequence of, the prosecution of that
unlawful purpose, Cassius Turvey received fatal injuries when
Mr Brearley repeatedly struck him with a pole that the appellant knew
Mr Brearley was armed with. In our view, that is distinctly more
serious than the circumstances in Hishmeh.
72 The starting point of a term of 11 years' imprisonment in Hishmeh
is the relevant point of comparison, given that there can be no discount
for a plea of guilty in this case. Even then, it must be remembered that
Hishmeh was decided when the maximum penalty for manslaughter
was 20 years, not life imprisonment.
100 Hishmeh [84].
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73 In our view, Hishmeh is entirely consistent with imposing a
sentence of 9 years on the appellant in this case. It certainly does not
indicate that this sentence was manifestly excessive.
74 Only one of the four cases relied upon by the appellant involves a
situation where an offender is sentenced for manslaughter upon the
basis that the relevant killing was carried out by another person who
was pursuing a common purpose with the offender. That is the
Queensland decision in R v Oram; R v Hinds.
75 That case is of no assistance in considering the customary
sentencing standards for the offence of manslaughter in Western
Australia. This court is required to have regard to decisions of
intermediate appellate courts of other jurisdictions in considering
sentences for Commonwealth offences. However, in the case of State
offences, comparable cases are those of this court and its predecessor,
the Court of Criminal Appeal.101 Sentencing decisions of courts in
other jurisdictions occur in the context of different crimes and
sentencing legislation and different sentencing practices which have
developed in those other jurisdictions. They also are concerned with
different offences created by the statutes of those other jurisdictions.
Reference to those decisions made in this very different context does
not assist in ensuring that the sentence imposed on an offender is
broadly consistent with sentences imposed in broadly comparable
cases. Nor does it assist in maintaining reasonable consistency in
sentencing for State offences. The offences, and legislative and
practical context in which sentences for those offences are imposed, are
simply too different.
76 In any event, even if regard were had to that decision, nothing in
the reasons of the Queensland Court of Appeal in upholding sentences
of 9 years' imprisonment imposed in Oram suggests that the appellant's
sentence of 9 years' imprisonment was manifestly excessive.
77 The other cases upon which the appellant relies do not involve a
person being convicted of manslaughter upon the basis that the victim
died as a probable consequence of another person's actions in the
pursuit of a common unlawful purpose. Rather, they are examples of
lesser sentences imposed for manslaughter in different circumstances.
78 In Francis, the appellant was 24 years old at the time of offending.
He was driving along a road at 7.20 pm in December 2016 when he
101 See, for example, Hodges v The State of Western Australia [2025] WASCA 136 [74(5)].
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noticed a 15 year old boy riding a trail bike. The appellant was
unlicensed at the time, as the result of being disqualified from holding a
licence for 9 months. The appellant thought he recognised the trail bike
which he saw the boy riding as the same trail bike that had been stolen
from his home 3 months earlier. He chased the boy on the trail bike in
his car, travelling at excessive speeds. In order to avoid the chase, the
boy entered a four way intersection, in breach of a give way sign. He
was hit by an SUV wagon entering the intersection with right of way,
and died as a result. The appellant drove up to the intersection, but
realised that the boy's trail bike was not the one stolen from him. He
left the scene without rendering any assistance.
79 The appellant pleaded guilty and was sentenced to a term of
5 years and 6 months' imprisonment in respect of the manslaughter
charge. This included a reduction of 20% on account of the guilty plea.
He was also sentenced for failing to stop and render assistance
(18 months cumulative) and failure to report an incident (18 months
concurrent). His total effective sentence was therefore 7 years. Both
the appellant and the State appealed against the term of the sentences,
on the opposite bases that the sentences were manifestly excessive or
inadequate. Both appeals were dismissed.
80 In our view, there is a different order of culpability between:
(i) making a decision upon the spur of the moment to chase a person on
a trail bike causing them to become involved in a fatal crash; and
(ii) being part of a group prosecuting a common unlawful purpose of
chasing children, and terrorising and potentially attacking them, while
one of the men was armed with a weapon. We do not find much
comparative assistance from Francis.
81 The third case referred to by the appellant is Broadby. This is
another decision of the Queensland Court of Appeal, which is of no
assistance for the reasons explained at [75] above, and because of the
very different circumstances in which a sentence of 9 years'
imprisonment was imposed in that case.
82 The final case upon which the appellant placed reliance is Hutton.
The appellant in that case formed the view that the victim had sexually
assaulted his daughter. The appellant went to the victim's house and
confronted him. He stabbed the victim to the left and right of his groin,
but the injuries which the victim sustained were not life threatening.
The appellant doused the inside of the victim's house with petrol and set
it on fire. When the appellant left the house, he knew that the victim
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had been injured, but he did not obtain any assistance for him.
Firefighters later found the victim's body at the rear of the property
outside a glass sliding door which connected the house to the backyard.
The glass sliding door was open. There was a garden hose near the
victim's body. Forensic pathologists determined that the cause of the
victim's death was the 'combined effects of fire and multiple injuries in
a man with atherosclerotic heart disease'.102
83 The appellant pleaded guilty to a charge of wilfully and unlawfully
destroying property (namely the house), and a charge of manslaughter.
He was sentenced to 18 months' imprisonment (reduced from 3 years
3 months) on the first charge, and 7 years 6 months' imprisonment for
the second count. Hence, the total effective sentence was imprisonment
for 9 years. The appellant appealed upon the basis that the term
imposed for manslaughter was manifestly excessive, and that the total
effective sentence was contrary to the first limb of the totality principle.
The appellant failed to obtain leave to appeal on either ground.
84 The violence actually used upon the victim was not itself
life-threatening, and was therefore substantially less than the violence
inflicted upon Cassius Turvey. There is no consideration in this case of
the position of an offender who is party to a common unlawful purpose,
but who does not carry out the acts which cause death. For these
reasons, we do not regard this case as helpful in defining a standard of
customary sentencing relevant to the present case.
85 For the reasons which we have set out, we do not regard the cases
upon which the appellant places reliance as setting any relevant range
or customary standard of sentencing. The closest analogy is the
decision in Hishmeh. This does not suggest that a sentence of 9 years
is out of line with sentencing standards, or is manifestly excessive.
Position in scale of seriousness
86 In our view, the salient features of the appellant's offending are the
following matters:
(a) the knowledge of the appellant that other members of the group
were preparing weapons, such as trolley poles and
knuckledusters, to participate in a fight;
(b) the presence of the appellant in the car chasing groups of boys,
who were on foot, around the grassed area;
102 Hutton [17].
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(c) the fact that the appellant was an adult, in a group of adults,
which was targeting a number of children;
(d) by the stage of the offending against Cassius Turvey, there was
no basis for thinking that any person being chased had anything
to do with the smashed windows on Mr Brearley's car. As the
trial judge said, the only purpose for chasing down one or more
children was 'about revenge and terrorising a group of kids for
its own sake'.103 The possibility of an innocent person being
targeted should have been obvious to the appellant, given his
knowledge of the incident involving Lucas Sheean just days
before;
(e) although the appellant departed from Mr Brearley and
Mr Palmer at the creek line, he maintained the unlawful purpose
of chasing children, and terrorising and potentially attacking
them, while one of the men was armed with a weapon, as is
evident from his yelling out 'get him';
(f) even after the brutal attack by Mr Brearley upon Cassius
Turvey, the appellant affirmed the unlawful purpose which had
been pursued, by making the video which celebrated that 'We
got 'em'.
87 All of these matters demonstrate the grave and serious nature of
the appellant's manslaughter offence. Moreover, the appellant was the
only accused to be involved in, and convicted of, every count on the
indictment in the events leading up to the murder of Cassius Turvey.
88 In our view, the appellant's culpability is substantial. Had he
participated in the attack itself upon Cassius Turvey, he would have
been guilty of murder, not manslaughter, as was the case for
Mr Brearley. That would have carried a much heavier sentence, and
would have reflected a greater degree of culpability. But it does not
follow that the appellant obtains substantial further mitigation, or that
the objective seriousness of his offending is substantially reduced, by
reason only of the fact that he did not participate in the acts which
killed Cassius Turvey. That circumstance is already substantially
reflected in the lesser offence of manslaughter of which he was
convicted.
103 SR [111] - [112].
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Appellant's personal circumstances
89 The appellant's personal circumstances were fully considered by
the trial judge. We have summarised his analysis of the appellant's
antecedents at paragraphs [50] - [51] above. In particular, the trial
judge took into account the appellant's age, potential remorse and
prospects of rehabilitation.
Disposition
90 Having regard to all of the circumstances of this case, and the
relevant and applicable sentencing principles, the sentence of 9 years'
imprisonment imposed for the manslaughter offence cannot be regarded
as manifestly excessive. The appellant's essential argument that the
sentence was manifestly excessive because he did not himself
participate in the beating which killed Cassius Turvey effectively
ignores his substantial culpability for what occurred. He joined in,
encouraged, and then affirmed by celebration, the pursuit of an
unlawful common purpose of chasing children, and terrorising and
potentially attacking them, while one of the men was armed with a
weapon. The children, who had done nothing wrong, were simply
walking about after school in the afternoon. A probable consequence
of this was that one of the children would be unlawfully killed, as in
fact occurred. The imposition of a sentence of 9 years' imprisonment
upon the appellant for his role was commensurate with the seriousness
of the appellant's offence. The sentence cannot be regarded as
unreasonable or plainly unjust.
91 While leave to appeal should be granted, the appeal should be
dismissed.
I certify that the preceding paragraph(s) comprise the reasons for decision of
the Supreme Court of Western Australia.
LH
Associate to the Hon President Thomson
6 AUGUST 2026
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