An Indigenous teen's drunk and "rowdy" alleged murderers armed themselves with metal poles and knuckle dusters, a witness has claimed before admitting he had lied under oath about events leading to the incident.
Cassius Turvey, a 15-year-old Noongar Yamatji boy, died in hospital 10 days after prosecutors say he was chased down, knocked to the ground and "deliberately struck to the head with a metal pole" in Perth's eastern suburbs on October 13, 2022.
Jack Steven James Brearley, 23, Brodie Lee Palmer, 29, Mitchell Colin Forth, 26, and Aleesha Louise Gilmore, 23, are on trial in the West Australian Supreme Court for his murder.
One of Gilmore's younger brothers, Tyler, told the jury on Thursday that he called his sister for help in the hours before Cassius was allegedly attacked.
"I was getting threatening messages and calls and stuff that people are meant to come to the house," Tyler said from the witness box.
"Smash it up and stuff."
Gilmore arrived at their family home - where her then-boyfriend Brearley also lived - in Palmer's black Ford Ranger ute with the other three accused, the court was told.
"They were getting like weapons and stuff," Tyler said under questioning from prosecutor Ben Stanwix.
"Brodie, he was breaking (shopping) trolley poles ... in the alleyway (beside the house).
"There were two or three ... I'd seen that he had knuckle dusters in his hand before that."
Tyler, who was 18 at the time, said the accused were "a little bit drunk" and "rowdy" before they drove off to look for the group of people they believed was threatening to damage the Gilmores' home.
Brearley, Palmer and Forth returned in the ute about 1.5 hours later and Gilmore walked home, he said.
"She went in her room, she was crying," he said.
"Jack came back in and they started arguing again and then my sister (self-harmed)."
He said Palmer and Forth drove Gilmore to the hospital, while Brearley stayed at the house.
Brearley later cut his hair to change his appearance "because he didn't want to get caught" but "halfway to finishing the cops rocked up and stormed the house".
Palmer's lawyer, former federal attorney-general Christian Porter, questioned the now-21-year-old Tyler over his evidence, comparing it to his statements to police and prosecutors in 2022 and early-January.
He targeted Tyler's assertion to the jury that only Palmer broke poles off the shopping trolleys and reminded him that a month earlier he said he'd also mentioned Brearley.
Tyler agreed he was guessing before admitting he lied to police in the days after Cassius died about not knowing why the allegedly armed group had left the house in Palmer's ute.
"You lied to police to protect Jack and Aleesha ... you just lied to the jury under oath a moment ago," Mr Porter said.
"Yes," Tyler responded.
Prosecutors allege Brearley struck Cassius in the head two times with a metal shopping trolley pole while "hunting for kids" because somebody had smashed his car windows.
They allege Forth, Palmer and Gilmore helped him and knew his intent before the incident.
Another teenage boy, who was at the Gilmore house on the day, told the court Gilmore wasn't with her co-accused when they allegedly murdered Cassius.
"She was home the whole entire time," the youth, who was a friend of Gilmore's youngest brother, said.
He also said Tyler and his younger brother agreed to fight the youths they were communicating with and arranged to meet at a site near where Cassius was allegedly attacked.
The boy said either Forth or Palmer put a baseball bat in the ute before they and Brearley "took off".
He said the trio "rocked back up" about 15 minutes later and "we seen Mitch holding Jack up, walking him back inside", with the court previously hearing Brearley was slashed with a knife about the same time Cassius was allegedly attacked.
"He couldn't walk. He was limping," he said.
13YARN 13 92 76
Lifeline 13 11 14
beyondblue 1300 22 4636
