FOUR people have been jailed for life for murdering a father whose body was found in his burnt-out car in Perth.

Travis Bennjamin Mills, 30, was severely beaten in his Seville Grove home, then driven in the boot of his car to a vacant lot in Hilbert, where the vehicle was set ablaze, burning him alive.

His partner Seleena Monique Ruthsalz and her mother Joanne Christine Ruthsalz, who was the instigator, will spend at least 21 years and 24 behind bars, respectively.

Darren Graeme Campbell and friend Darryl Raymond Newton, who together carried out the attack in April last year, were each jailed for at least 24 years.

Cambell’s wife Justine Claire Campbell — who played a central role in arranging the murder, was one of Joanne Ruthsalz’s drug associates and pleaded guilty on the first day of the trial — was imprisoned for a minimum of 13 years.

In a bid to give herself an alibi, Seleena Ruthsalz went to her mother’s house on the night of the killing while Mr Mills stayed home to build a trampoline for their daughter Ruby, who turned one the next day.

She arranged for the keys to be handed to the armed men, who caught Mr Mills by surprise and took him from the house covered in blood from the beating.

The WA Supreme Court heard Mr Mills despised Joanne Ruthsalz for her drug dealing, shady associates and “filthy house”, and didn’t want his daughter exposed to that.

Camera Icon Travis Mills, 30, with his baby daughter. Mr Mills was found murdered in the boot of his car in Hilbert in Perth's south-east. Credit: Supplied

Camera Icon Travis Mills, 30, with his baby daughter. Mr Mills was found murdered in the boot of his car in Hilbert in Perth's south-east. Credit: Supplied, Facebook

Prosecutor Carmel Barbagallo said Joanne’s hatred for him in return was “the genesis of evil” for what followed, spinning a “web of lies” that he was abusive towards her daughter and granddaughter, and mistakenly thought he might take Ruby to Queensland.

The court heard Joanne exploited Justine’s trauma over a previous physically abusive relationship, which gave her the misguided motive of wanting to protect Seleena and Ruby.

Justice Stephen Hall said Seleena might have initially thought her partner was just going to be beaten, but knew she was seeing him for the last time when she left that night.

She tended to acquiesce to her mother, who “wanted a more permanent solution” and “pushed hard for it”.

Ms Barbagallo said a “perfect storm” was brewing between the three women, while Justice Hall said it was “somewhat chilling” Newton was “willing to kill for no reason other than to assist a friend”.

The court heard Darren Campbell originally wanted no part in the plot and urged his wife to stay out of it, but capitulated when Newton’s planned accomplice dropped out.

Mr Mills’ family and friends applauded and cheered when Seleena was sentenced.

While Justine wept during Friday’s sentencing, especially when it was revealed she had been severely beaten in prison for testifying against the others, the Ruthsalzes were expressionless.

Justice Hall said Mr Mills was executed with extreme brutality.

“Travis Mills did not deserve to die, let alone in the way that he did,” he said.

Mr Mills’ parents told reporters outside court the sentences were just.

“His daughter Ruby will never get to meet the incredible man that loved and adored her,” the victim’s mother said.