National

WA courthouse murderer jailed for 24 years

By AAP Newswire

A bitter custody dispute ended with Paul Gary Turner fatally stabbing the mother of his two children using lethal commando techniques in a Perth courthouse.

Turner, 43, who has been jailed for life with a minimum of 24 years, stabbed 33-year-old Sarah Marie Thomas six times during a mediation session inside Joondalup Justice Complex on December 20, 2016.

One of three stab wounds to the neck cut her carotid artery, which killed her within seconds.

Administration worker Crystal Sudholz testified during Turner's trial she heard muffled yelling then a "horror movie scream" before the registrar ran out of the conference room, shouting for security and an ambulance.

CCTV footage showed Turner then walked out into the waiting area, slid against a wall to the floor and put his hands in his lap.

During sentencing on Tuesday, prosecutor James Mactaggart described the look on Turner's face as "smug", having taken the opportunity to "make a very public statement".

"This was a crime of quite outrageous violence," Mr Mactaggart said.

The pair had been embroiled in an increasingly tense dispute over custody of their children and the seemingly cordial meeting was about his claim she owed him money.

Moments before the attack, Ms Thomas declined to make an offer.

Turner denied responsibility, saying a workplace accident in 2015 left him suffering seizures that caused memory blackouts.

He claimed he recalled being at home that morning then regained his senses at a police station.

"I remember looking at my hands and they're covered in blood," Turner testified, crying.

Supreme Court of WA Justice Joseph McGrath labelled Turner's claim he was in a dissociative state "a concoction" but accepted he had in the past suffered from "some form of dissociative seizures".

Turner's defence counsel Lisa Boston conceded there was an intention to kill, but said it had only been planned that morning following mounting stress and long-term depression.

Justice McGrath said he was unable to find there was any planning before that.

"The evidence is compelling that you went to the courthouse with the intention of killing the deceased," he said.

Having taken a knife from home and hidden it either in a folder or in his shorts, he then calmly inflicted the lethal wound, targeting the carotid artery as he has been extensively trained to do, knowing it would lead to certain death.

"When the deceased was vulnerable, you murdered her," Justice McGrath said.

He said Turner appeared to have shown limited remorse.

The victim's devastated sister Emma Howden said the sentence showed judges were taking domestic violence cases very seriously.

Steps should be taken to make sure people in her position were safe in court complexes, Ms Howden said.

"She should have been safe and she wasn't.

"Everybody has that right, whether it be male, female, it doesn't matter, they should be safe and secure walking into a government building at all times."

Ms Thomas' father Greg Thomas said he would never be satisfied as he would not get his daughter back.

"No sentence is enough."

During his testimony, Turner admitted he trained in lethal weapon techniques over three years and demonstrated, using gestures, how to swiftly kill by severing the carotid artery.

"You'd insert the blade behind the muscle and rip forward,' he said.