Hillier triple murderer Steven Graham Peet finally pleads guilty, after delaying trial for months with mental health claims

HILLIER triple murderer Steven Graham Peet has finally confessed to his evil crimes after delaying his case for months with mental health claims and devastating his victims’ families.

• ‘I murdered a mum but not her kids’ — Hillier killer’s shock plea
• Analysis: Case confused, family traumatised by killer’s plea
• Hillier case grandfather has ‘lost faith’ in prosecutors
• Hillier killer ‘is not mentally incompetent and has confessed’

HILLIER triple murderer Steven Graham Peet has finally confessed to his evil crimes after delaying his case for months with mental health claims and devastating his victims’ families.

Peet’s beleaguered, delay-plagued trial — over the deaths of Adeline Yvette Wilson-Rigney and her children in 2016 — was supposed to resume in the Supreme Court on Monday.

He admitted murdering Ms Wilson-Rigney, 28, but denied killing her daughter Amber, 6, and son Korey, 5, claiming he was in a “disassociative state” when they died.

After another, two-hour delay on Monday morning, defence counsel Bill Boucaut SC asked the charges be read to his client again.

Asked if he had murdered Amber, Peet lowered his head, sighed and answered: “Guilty.”

Asked if he had murdered Korey, Peet paused, swallowed hard and answered: “Guilty.”

The pleas prompted an emotional response in the courtroom’s packed public gallery.

The children’s maternal grandmother, Donna Rigney, put her head on her knees while their paternal grandfather, Steven Egberts, and his partner Janet Wells openly wept.

Steven Graham Peet following his arrest. Picture: Emma Brasier.

Peet, 31, will receive a mandatory life sentence for murdering the family at Hillier, north of Gawler, in May 2016.

He fatally bashed and strangled Ms Wilson-Rigney — known to friends and family as Yvette — while arguing about their relationship.

Ms Wilson-Rigney had decided to leave Peet who, prosecutors said, was “infatuated” with her, for a former boyfriend.

Peet murdered her, leaving her body in the laundry under a mattress, before attacking the children.

Both were found with cable ties around their necks, and had been hogtied with layers of sticky tape around their heads.

Peet had stuffed a sock in Amber’s mouth and left her body in her room beneath a stack of clothes.

Adeline Yvette Rigney-Wilson, 28, and her children Amber Rose Rigney, 6, and Korey Lee Mitchell, 5. Picture: Supplied

Korey, who was found under a play tent, had managed to remove some of the tape, and injuries to his tongue suggested he may also have been gagged with a sock.

Police would later find cable ties on the doors of a wardrobe, the back of which had been “kicked out from the inside”, suggesting the children had been placed in it.

Either during or immediately after the murders, two Families SA workers visited the home to tell Ms Wilson-Rigney they had secured furniture for Amber and Korey.

They would later tell police the house was “quiet” and they left.

In the hours following the murders, Peet drove to the home of a friend — whom he considered an uncle — and said “I f**ked up, I need you to come for a drive”.

On the drive back to Hillier, he asked “what’s the best way to get rid of a body, should I chop it up?’ and “how do you think I should get rid of the car?”.

Upon seeing the murder scene, that man and another — Ms Wilson-Rigney’s neighbour — physically attacked Peet.

Steven Egberts, grandfather of victims Amber and Korey, at Adelaide court with his partner Janet Wells. Picture: Dylan Coker

Peet would go on to confess no less than six times — once to a 000 operator — and would claim Ms Wilson-Rigney had subjected him to domestic violence.

When his trial began in August, however, Peet would only admit he murdered Ms Wilson-Rigney.

He pleaded not guilty to having murdered the children, leaning on a psychological report suggesting he may have been in a “dissociative state” when they died.

Defence counsel would claim that, due to his mental state, Peet had lacked the ability to consciously choose to kill and therefore could not be guilty of murder.

The claim derailed the trial, sending prosecutors in search of their own mental health expert to counter the defence case.

Mr Egberts — Amber and Korey’s grandfather — soon lost faith in prosecutors, saying they had shown him no empathy and “misled” his family.

Two weeks ago, Justice Malcolm Blue was told both sides were ready to resume the trial.

Donna Rigney, the mother of murder victim Yvette Wilson-Rigney outside of court. Picture: Dylan Coker

Prosecutors said they would call not only expert mental health evidence but also the witnesses to whom Peet allegedly confessed.

On Monday, defence barrister Bill Boucaut SC asked for a further two-hour delay.

“There will need to be some discussions with my client owing to some recent developments,” he said.

“We’d ask the matter be held until midday so that we can speak with him.”

At 12pm, he asked the charges be read to Peet again — and the murderer confessed.

“Your Honour was aware the issue in this case was one (arising from) the opinion expressed, by the psychologist, of disassociation,” Mr Boucaut said.

“Having received (the prosecution expert’s) report and considered material that had not previously been known to him, mid-last week that psychologist provided a report wherein he revised his opinion.”

Justice Blue remanded Peet in custody for sentencing submissions on Friday.

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