Four on trial in WA over ex-lover's murder

A woman lured her former lover into an "ambush" where three men helped her run him over and repeatedly shot him during a drug and alcohol-fuelled binge, a Perth murder trial has heard.

Tamara Kathleen Broadbent, Kym Steven Foster, Damien Paul Kosick and Gary David Young are on trial in the West Australian Supreme Court charged with murdering David Blenkinsopp.

The father of two went missing from Wanneroo, in Perth's north, in March 2012 and his body was found buried in bushland in nearby Pinjar later that month.

In his opening address on Wednesday, prosecutor Bruno Fiannaca said Mr Blenkinsopp, who was a bi-polar drug user, was having an affair with Broadbent in 2011.

Their "turbulent" relationship was at times violent and by February 2012, she began dating Foster, and took out a restraining order on her former lover, which he then broke.

On March 4, Broadbent, Foster, Kosich and Young went on a drug and alcohol binge while Mr Blenkinsopp did the same elsewhere when their worlds collided in a "cauldron of simmering anger" when Broadbent invited Mr Blenkinsopp out, Mr Fiannaca said.

"She was luring him, ladies and gentlemen, into an ambush," Mr Fiannaca said.

"He simply did not stand a chance." The four accused confronted an unarmed Mr Blenkinsopp to "eliminate" him by shooting him twice in the torso and once in the leg with a rifle.

He was also run over, with the blood leaving a "landmark" at the scene when police later investigated, Mr Fiannaca said.

They then put him in the car and buried him in Pinjar before Broadbent fired more shots at Mr Blenkinsopp's body.

Mr Fiannaca said it was a pre-meditated murder fuelled by alcohol and drugs.

The trial continues.