30 years for brutally murdering a mum and her kids
THE man who beat a young mother to death before fatally binding and gagging her two children will serve at least 30 years in jail - five years less than SA's last triple murderer.
On Friday, the Supreme Court sentenced Steven Graham Peet to life imprisonment with a non-parole period of 30 years.
Justice Malcolm Blue dubbed the murders of Adeline Yvette Wilson-Rigney, Amber Rose Rigney and Korey Lee Mitchell were "incomprehensible" and "reprehensible".
However, he deemed Peet's guilty pleas - after months of delay caused by his claims of mental impairment - and remorse were worth a sentence reduction of almost 10 per cent.
In contrast, triple murderer Jason Alexander Downie was jailed for life with a 35-year non-parole period for his crimes at Kapunda in 2010.
Unlike Peet, Downie was still a teenager both at the time of the murders and when he was sentenced - and none of his victims were young children.
The court's decision - which prompted the children's grandfather to leave the court in anger - is expected to reignite debate over the sentencing of multiple murderers.
Last month, the Homicide Victim Support Group called for an overhaul that would see such killers serve consecutive life terms, as happens in some US jurisdictions.
Peet, 32, murdered the family at their Hillier home on May 30, 2016.
Ms Wilson-Rigney, 28 - who had been in a relationship with Peet - was beaten with a crowbar and strangled with a cable tie, and her body left under a mattress in the laundry.
Amber, 6, had a cable tie around her neck and had been hogtied, with a sock taped into her mouth, and left under a pile of clothes.
The body of Korey, 5, was found in his room under a play tent - he, too, had been tied up but had managed to remove the sock from his mouth before he died.
All three died around the time two Families SA workers, who had been dealing with the family, knocked on the door of the house.
They had attended to tell Ms Wilson-Rigney they had secured furniture for the children.
Peet confessed his involvement to multiple people in the hours following the murders, including a 000 operator and two men who assaulted him when they found the bodies.
Despite those admissions, he pleaded not guilty to Ms Wilson-Rigney's murder when his trial began in August last year.
He claimed he was not criminally liable for the children's deaths because he was in a "disassociative state" at the time.
Peet blamed that state on Ms Wilson-Rigney, claiming she had subjected him to domestic violence during their relationship.
His claim, which caught prosecutors off-guard, prompted a five-month delay in the case while mental health experts were consulted.
During that time, Amber and Korey's paternal grandparents lost faith in "heartless" prosecutors who had, they said, shown an "appalling lack of empathy" toward them.
When his trial resumed in January, Peet pleaded guilty to having murdered the children - the court heard expert analysis did not bear out his purported disassociation.
Psychological reports, subsequently released to The Advertiser, showed Peet's own account of the incident was incompatible with his claim and had derailed it.
Prosecutors asked Peet be sentenced on the basis he had murdered the children because they were eyewitnesses to their mother's death.
Peet's counsel doubled down on the domestic violence claim, saying he suffered from "battered wife's syndrome" and had finally "reacted" to the abuse he endured.
The children's grandparents, meanwhile, urged the court to "do justice for our beautiful angels", saying the murders had effectively killed them as well.
In sentencing on Friday, Justice Blue paid tribute to the families' statements, and said listening to them was "a very moving and profound experience".
WORST OF THE WORST: SA'S LONGEST NON-PAROLE PERIODS
John Justin Bunting and Robert Joe Wagner: life without parole for the "bodies in the barrels" serial killings in the 1990s.
Mark Errin Rust: life without parole - due to his uncontrollable sexual urges - for the murders of Maya Jakic and Megumi Suzuki in the 1990s.
Dieter Pfennig: life with a combined 60-year non-parole period for the murders of Louise Bell in 1983 and Michael Black in 1989.
Jason Alexander Downie: life with a 35-year non-parole period for the 2010 murders of Andrew, Rose and Chantelle Rowe.
Jean Eric Gassy: life with a 34-year non-parole period for the 2002 assassination of Dr Margaret Tobin.
Angelika Gavare: life with a 32-year non-parole period for the 2008 dismemberment murder of pensioner Vonne McGlynn.
Garry John Collie: life with a 30-year non-parole period for the murders of two people during an early 2000s drug deal.