A meth addict who attacked an innocent man as he walked through a park in Adelaide's south will spend at least 25 years behind bars for the murder.
Shaun Thomas Russell, 36, was 250 metres from home as he walked through Hackham West Reserve after watching some of the AFL grand final at a friend's house in September 2019 when Robert Joseph Patard beat him to death with a garden stake.
The 45-year-old was in a "volatile and angry state" after arguing for most of the day in the park with a woman, and he "simply erupted" when Mr Russell walked towards him, pulling up a large wooden garden stake and striking him with it at least three times.
Patard then discarded the stake behind some trees and told a family not to enter the park.
Patard changed his plea to guilty four days into his murder trial.
During sentencing in the Supreme Court, Justice Anne Bampton said Patard had taken methamphetamine the night before and he had no right to be in the park that day in such an angry state.
"Mrs Russell [Shaun's mother] spoke about Shaun Russell being in the wrong place at the wrong time. He was not," Justice Bampton said.
"He had every right to be in a public place making his way to his home.
"It was you, in the grip of the uncontrolled anger and sexual possessiveness that underpinned your violent killing that had no right to be in that public place."
Patard's lawyer, Nick Healy, previously told the court Patard was sorry for murdering Mr Russell and now took full responsibility.
Patard has been sentenced to life in prison with a non-parole period of 25 years, backdated to November 2019 when he was taken into custody.
Outside court, Mr Russell's mother Dawn said the family felt they had received justice.
"We're glad it's over, it's been two-and-a-half years," she said.
Mrs Russell said it was a "great outcome" but at the same time it was a "sad day".
"There's really no winner here, it's sad for both families," she said.
Mrs Russell described her son as a "very kind-hearted", generous and forgiving person who loved his family.
