A man who stabbed a teenager to death after a party in suburban Perth has been sentenced to at least 19 years in prison.
Chikayne Heslip died after he was attacked by a group in Waikiki, south of Perth, in December 2020.
The 17-year-old was repeatedly assaulted while he was on the ground, with Kingston Trey Coomer stabbing the teenager dozens of times.
The court heard there were 41 injuries to his head, neck, torso and limbs, and at least 32 of them were stab wounds.
The attack happened after a party had ended, and youths gathered in the street outside.
Victim assaulted 'while unable to defend himself'
Fights had broken out and Chikayne Heslip was chased in the belief he'd thrown a bottle, although Justice Michael Corboy told the court there was no evidence he did.
Justice Corboy said he was assaulted and knocked unconscious "while unable to defend himself" and in a vulnerable position after tripping over and falling on Resolution Drive, while others filmed the events on mobile phones.
He described it as a "vicious" group assault, which occurred in front of young people, and these were aggravating factors.
Coomer's co-offenders had already been sentenced for doing an act likely to cause harm, while Coomer was found guilty of murder after a jury trial earlier this year.
Justice Corboy said Coomer must have attended the party with a knife and while he had no reason to attack Chikayne Heslip, he showed a "relentless desire to harm" him.
Justice Michael Corboy said the teenager's life had been taken by a "senseless and inexplicable act of violence".
He told the court "public social gatherings are all too frequently marred by violence" carried out by young males.
He said this was "obviously intolerable" and there needed to be a message sent to the community that those who engaged in such behaviour would be punished.
'We will never forgive you': mother
Chikayne's mother read a statement to the court, describing how her family's life changed forever when her son was killed, describing him as "a friend to many and a brother for life" to his mates.
She said he was a "gentle giant with a heart of gold" and his death was "incomprehensible".
Addressing Coomer, she said "we as a family will never forgive you".
The Supreme Court heard that Coomer, who was 18 at the time of the murder, had multiple convictions as a juvenile, including for violent crime.
Justice Corboy accepted he'd had a dysfunctional and deprived childhood, marred by violence and substance abuse in his family home.
Coomer started using drugs at 15
He was taken into state care as a result of his parents' use of methylamphetamine and he was moved into many group homes.
The court heard Coomer, who'd started using cannabis at 15, had an anti-social personality as a result of exposure to violence.
While his youth and his dysfunctional upbringing were factors in his favour in sentencing, the court heard Coomer was at high risk of reoffending and Justice Corboy said the community had to be "adequately protected".
There was some applause from the public gallery after the 19 year minimum sentence was imposed.
Coomer, who was wearing a face mask, showed no reaction but did turn to look at relatives seated in the gallery.
