A teenage love triangle allegedly sparked a series of events that led to alleged murder of Perth schoolboy Cassius Turvey

A teenage love triangle allegedly sparked a series of events that led to a 15-year-old boy who had nothing to do with it being killed, a court has heard.

A teenage girl at the centre of a love triangle which allegedly sparked a series of events that ended with the death of 15-year-old Cassius Turvey has given evidence of confrontations with four people accused of his murder.

Jack Brearley, 23, Aleesha Gilmore, 23, Mitchell Forth, 26, and Brodie Palmer, 29, are on trial in the WA Supreme Court over the alleged murder of Cassius Turvey in Perth’s east in 2022.

A fifth man Ethan McKenzie, 20, has been charged with the deprivation of liberty and assault of two teenage boys days before Cassius was allegedly attacked.

Mr Brearley, Mr Forth and Ms Gilmore are also facing additional charges over the same incidents.

Cassius Turvey’s mother, Mechelle Turvey, arrives at court supported by friends and family. Picture: NewsWire/ Emma Kirk

The state alleges a teenage love triangle involving Ms Gilmore’s 14-year old brother, a girl and another boy she dated for a number of days before him, led to the accused “hunting down” schoolchildren.

Ms Gilmore along with her boyfriend Mr Brearley, Mr Forth and Mr McKenzie went out in a car to pick up her younger brother who feared he was going to be mobbed on October 9, 2022.

But instead of going home after they picked up Ms Gilmore’s brother and his friend, the state alleges the group drove around looking for the boys who threatened her brother.

The state alleges a 14-year-old boy was forced to get into the car at knifepoint.

Another boy allegedly tried to flee the group on foot but was chased down, punched, kicked and stabbed on a suburban street before being forced into the car.

Jack Brearley, 23, is accused of murdering Cassius Turvey, but denies the allegation claiming the 15-year old boy stabbed him first and blamed co-accused Brodie Palmer of fatally striking the boy.

The girl told the court on Wednesday a car with Ms Gilmore and Mr Brearley pulled up on a road while she was waiting for a bus with friends.

She said Mr Brearley got out of the car and appeared mad screaming at the girls asking where all the boys went.

She said the accused got back into the car and yelled, ‘You better not be lying to us’ and drove off.

“I seen (Ms Gilmore) and her boyfriend in the front, and (two boys) in the back.

“Jack said those things, he came out of the car, he didn’t come too close and was screaming at us.

“He was pretty mad.

“They drove off and threw something out of the car, then five minutes later they came back and got the thing they threw out of the car and drove off.

“I think it was a bag.”

State Prosecutor Benjamin Stanwix has called the first witnesses in the Cassius Turvey murder trial. Picture: NewsWire/Philip Gostelow

The girl said she and her friends caught a bus to Jane Brook, a suburb in Perth’s east. When they got off the bus the car pulled up again and Ms Gilmore asked if they were okay.

“There were two boys spawned in the back, one had blood all over him,” she said.

Another witness, who was aged 12 at the time, recalled a car drove up on the footpath while she was waiting at the bus stop with her friends.

She told the court a boy called Mitchell or Michael got out of the car and was angry, he told them he would “smash their head in” if they were lying.

She said she saw the car again in Jane Brook and a boy whose hands were covered in blood was in the back.

The state alleges a few days before Cassius Turvey was murdered a group of 20 somethings snatched two other boys off the streets in Swan View after Aleesha Gilmore’s brother was threatened over a teenage love triangle.

The state alleges a few days after four of the accused snatched two boys off the streets in Swan View, a group of schoolchildren smashed the windows of Mr Brearley’s car while it was parked outside the home where he lived with Ms Gilmore, her father and two younger brothers.

Cassius was attacked the following day, on October 13, 2022, when Mr Brearley, Ms Gilmore, Ms Forth and Mr Palmer allegedly drove around looking for school kids who threatened Ms Gilmore’s brother.

When they came across a group of about 20 children, the state alleges it was Mr Brearley who struck Cassius twice to the head with a steel shopping trolley handle which split his ear, lacerate his forehead and caused brain damage.

He died in hospital 10 days later from complications caused by his injuries.

Mr Brearley has denied the allegation, claiming Cassius stabbed him first then blamed co-accused Mr Palmer for delivering the fatal blows.

Mr Palmer claims he never got out of his vehicle when they came across the group of schoolchildren.

Ms Gilmore alleges she had gotten out of the car after getting into an argument with Mr Brearley earlier and was about 1km away at the time.

The trial continues.