Travis Kirchner, 44, said he became angry and used a concrete owl pedestal to fatally bash 54-year-old Sally Rothe.

Kirchner appeared in the Supreme Court on Monday after pleading guilty to Ms Rothe's murder at Murray Bridge, in the state's southeast, earlier this year.

Derek Kordick, for Kirchner, said he had been drinking alcohol before he went to her home to collect some of his belongings, which had been stored there.

Kirchner and Ms Rothe had never been in a relationship or lived together.

Revealing the motive for the murder for the first time, the court heard Kirchner reacted violently after Ms Rothe tapped him with a frame.

Mr Kordick said he used part or all of the 40-kilogram owl pedestal to assault Ms Rothe for at least 40 seconds.

"He is a man who resorts to violent means in conflicts he cannot control," he said.

Police later discovered Ms Rothe's body dumped in a garbage bin after responding to reports of a disturbance at her home.

Kirchner had fled the scene, sparking a five-day manhunt across SA and Victoria.

He was eventually arrested in the Melbourne suburb of Doveton after a tip-off, along with two others who were charged with assisting an offender.

In victim impact statements read to the court in October, Ms Rothe's family remembered the mother-of-three as a "beautiful soul" who fell victim to a heinous crime.

"Travis Kirchner's extremely violent actions have had a devastating effect on myself and my family," her sister Christine McMurdo said.

"Why would a man my sister hardly knew want to murder her?

"I believe society has no place for him apart from jail."

Justice David Peek will sentence Kirchner next year.

Australian Associated Press