Adelaide man admits partner's murder

The 86-year-old mother of murder victim Deborah Balbi will travel from Italy to Adelaide to be in court when her daughter's killer faces sentencing submissions.

Michael Lyall Johnson on Monday pleaded guilty in the Supreme Court to the murder of his partner Ms Balbi, 38, in December 2012.

Prosecutor Emily Telfer told the court that Mary Balbi had made arrangements to be in Australia for two weeks during the sentencing process.

She said a number of victim impact statements would be presented to the court.

Defence counsel Craig Caldicott is also seeking a psychiatric report on his 45-year-old client with the case adjourned until July 3 to allow time for it to be prepared and considered.

It was originally thought Ms Balbi had died of a drug overdose but after a lengthy police investigation, it was eventually determined she was strangled.