SA cold case killer jailed for 15 years

A man who bludgeoned a friend to death acted in a "mad rage" hitting his victim in the head until he felt his skull collapse, a court has been told.

In what was one of South Australia's most enduring cold cases, Adrian Stewart Mahony, 67, killed Dale McCauley, 43, at the victim's home at Willunga, south of Adelaide, in January 1998 before dumping his body in scrub nearby.

Mahony was not arrested until 2016 after advances in DNA techniques linked him to the man's disappearance.

Jailing him for at least 15 years on Thursday, Supreme Court Justice Malcolm Blue said the brutal murder was sparked by Mahony's anger at his friend's decision not to go ahead with a plan for the pair to restore a boat and move to Queensland to start a business together.

"You grabbed a nearby metal pipe, yelled his name and struck him in the head in a mad rage," the judge said.

"You struck him several times until you felt part of his skull collapse. At that time you realised he was dead."

Mahony then placed a cloth over Mr McCauley's face and talked to him for five minutes before concealing his body in nearby scrub.

He was interviewed by police at the time but was only arrested after a match was made in late 2015 between blood found in his car and Mr McCauley's DNA.

A video plea from the dead man's sister, which was shown to Mahony in detention, then prompted him to disclose the isolated location where he had left the body.

Justice Malcolm Blue said that allowed closure for Mr McCauley's family in circumstances where the dead man's body might otherwise have never been found.

After sentencing submissions last month, Mr McCauley's sister, Sandra Cole-Stokes, said it came as a shock that her brother's remains had finally been located.

And outside court on Thursday, a longtime friend of the dead man, Chris Hicks, said he believed justice had finally been done and he welcomed Mahony's decision to admit his crime and lead police to the body.

"Obviously, it had been playing on his mind for so long, he's probably relieved now and everybody else is relieved that knew Dale as well," Mr Hicks said.