A Perth woman has pleaded guilty to murdering young Perth father David Houston.
Amanda Jane Kelly, 20, appeared via video link in the Stirling Gardens Magistrate's Court this morning where she pleaded guilty to the charge.
Kelly's boyfriend Jonathan Robert Lee, 23, and another man, Samuel Jacob Walker, were jailed last month for at least 12 years for their role in the 24-year-old's murder at a South Fremantle house in May.
Mr Houston's body was found in a shallow grave near the coastal town of Binningup, 130km south of Perth, on June 2.
Sentencing Lee and Walker in December, Supreme Court Justice Eric Heenan said the murder was a "terrible crime committed in an orgy of drug abuse" and it highlighted the unpredictable and terrible consequences of substance abuse.
The court was told Mr Houston had been drug-affected and outnumbered when he was attacked at Walker's South Fremantle home on May 12.
The court had earlier been told that after a day of consuming cannabis, Walker offered to buy methamphetamine for the trio, and returned to the house with Houston, whom he’d known for a few weeks.
After Walker told Kelly he was gearing up to kill Mr Houston, she disappeared into the bathroom with Lee to have sex in the shower - returning to see Walker with a ligature around the victim’s neck.
After being urged to help, Lee hit Mr Houston in the face so hard his eye popped out of his socket, as Walker continued to choke him.
The pair dragged the man to the shower, then Lee repeatedly kicked him in the chest.
The male pair then wrapped his body in a barbecue cover and Walker drove the corpse in a Bunnings ute to the remote site where he was buried, along with quantities of acid and building materials.
Police traced the burial site through the GPS unit in the hired vehicle, and the pair were arrested.
Walker and Lee were each sentenced to life jail sentences with a minimum of 12 years.
Kelly, who is in custody at Bandyup Women's Prison, will be sentenced in the Supreme Court on April 5.