Cassius Turvey, 15, died in hospital 10 days after he was chased into bushland and beaten with a metal pole in Perth's eastern suburbs on October 13, 2022.
Jack Steven James Brearley, 24, and Brodie Lee Palmer, 29, were convicted in May of murdering the Noongar Yamatji boy after a mammoth 12-week trial.
Mitchell Colin Forth, 27, who was also on trial in the West Australian Supreme Court for Cassius' murder, was found guilty of manslaughter.
The trio's two-day sentencing hearing is set to start on Thursday.
The trial heard Brearley delivered the fatal blows while "hunting for kids" because somebody had smashed his car windows.
It was alleged Forth and Palmer aided him, and along with Aleesha Louise Gilmore, 23, who was acquitted of the murder charge, had a common purpose on the day.
The jury was told the attack on Cassius in bushland near a creek was "the end point of a complex series of events that had absolutely nothing to do with him".
They started on October 9 when Forth, Brearley, Gilmore and another man who was also on trial for lesser charges, Ethan Robert MacKenzie, 20, allegedly "snatched two kids off the street" and unlawfully detained them, punching, kicking and stabbing one of them.
That incident was allegedly sparked by a "love triangle" involving Gilmore's 14-year-old brother Cody, his then-girlfriend, who cannot be named for legal reasons, and her ex-boyfriend.
Three days later, on October 12, a group of school-aged kids allegedly went to Gilmore's home and "almost certainly in retribution" smashed the windows of Brearley's car.
Mr Stanwix told the jury it was "tit-for-tat escalation", and Brearley and Forth had later used a car as a weapon and chased down two boys, hitting one of them.
The following day, Gilmore's brothers warned that a group of teens could be coming to their family home, where Brearley also lived, looking for a fight.
Brearley and his co-accused allegedly armed themselves with metal poles pulled from shopping trolleys before driving off to search for youths.
About the same time, Cassius and a group of about 20 fellow students caught a bus to the same area to watch a fight being talked about on social media.
Brearley, Forth and Palmer intercepted them near the field, and Cassius and some other "terrified school kids" fled into nearby bushland.
"Cassius didn't make it as far as the fence when the accused Brearley caught up with him," prosecutor Ben Stanwix said.
"He was caught, knocked to the ground and deliberately struck to the head with a metal pole."
Cassius was struck at least twice, the impact splitting his ear in half and causing bleeding in his brain.
His death shocked the community and the attack was described by some, including Prime Minister Anthony Albanese, as racially motivated, although Mr Stanwix said this wasn't the case in his opening remarks.
All told, the five defendants variously faced 21 charges over the events of October 9 and 13.
The jury found them guilty of all except Gilmore's murder charge and a theft charge faced by Brearley.
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