Four people found guilty of murdering a young father whose body was found in his burnt-out car in Perth's southeast last year have been sentenced to life in prison.
Travis Mills, 30, was beaten with a baseball bat in his Seville Grove home then taken in the boot of his car to a vacant lot, where it was set alight, burning him alive on Good Friday 2015.
His partner Seleena Ruthsalz and her mother Joanne Ruthsalz will spend at least 21 years and 24 behind bars, respectively.
Justine Campbell, who played a central role in arranging the murder, was one of Joanne's drug associates and pleaded guilty at the last minute. She was imprisoned for a minimum of 13 years.
Justine's husband Darren Graeme Campbell and her friend Darryl Raymond Newton, who carried out the attack, were both jailed for at least 24 years.
A packed public gallery filled with Mr Mills' family and friends erupted into applause and loud cheers when Seleena Ruthsalz was handed her sentence, prompting Justice Stephen Hall to warn he would clear the court if there was another outburst.
"He was executed with extreme brutality," Justice Hall said.
"This was an extremely serious case of murder, aggravated by the way Travis Mills was killed.
"Travis Mills did not deserve to die, let alone in the way that he did."
While Campbell wept at various times during Friday's sentencing, especially when it was revealed had been beaten in prison for testifying against the others, the Ruthsalzes were expressionless.
Campbell - who bought methylamphetamine from Joanne Ruthsalz, sold her cannabis and played a central role in arranging the murder - pleaded guilty before the trial commenced.
Campbell and Newton carried out the attack when Mr Mills was home alone building a trampoline, a birthday gift for his daughter Ruby, who turned one the next day.
Prosecutor Carmel Barbagallo told the court during opening submissions that Mr Mills and Joanne loathed each other.
Mr Mills did not like Ruby being taken to her house, because she dealt drugs including heroin, while Seleena Ruthsalz manipulated Campbell - who had previously been in an abusive relationship - by claiming that she feared him.
Seleena Ruthsalz suggested Mr Mills planned to take Ruby and move to Queensland, but that was nonsense, Ms Barbagallo said.
The court heard Seleena and her mother cleaned up Mr Mills' blood at the Seville Grove house.
- AAP