Adelaide man Peter Rex Dansie has been sentenced to life in prison, with a non-parole period of 25 years, for murdering his wife in Adelaide's parklands in 2017.
Dansie, 71, drowned his 67-year-old wife Helen Dansie by pushing her wheelchair into a pond at Veale Gardens in Adelaide.
Justice David Lovell established a "dual motive" for the murder — a deterioration in Dansie's feelings for his wife and an interest in pursuing a sexual relationship with another woman in China.
The court previously heard Dansie was scheduled to fly to China, but the day before he was due to leave police searched his home and found a suitcase packed with condoms, Viagra, sex toys and lingerie.
During sentencing, Justice Lovell said Mrs Dansie's murder was the "ultimate act of domestic violence" and described it as an "evil and despicable act".
"This was a chilling, planned murder of a person whose only mistake was to trust you," he said.
"It was a planned murder — I'm not able to say precisely when you formed the intention to murder Helen.
"Clearly it was taking shape in the months leading up [to] that Easter Sunday."
He said Dansie made "no attempt" to save his wife once she was face-down in the pond at Veale Gardens.
Dansie — who is appealing against his murder conviction — was found guilty in December.
During the trial, prosecutors alleged Dansie murdered his wife because he regarded her as a cost burden.
Mrs Dansie, a former microbiologist, suffered a stroke in the 1990s that left her with long-term disabilities.
She was on an indexed pension for life, a large portion of which Mr Dansie was entitled to as her full-time carer, the court previously heard.
Family calls for review to protect 'the most vulnerable'
Helen Dansie's friend, Eugenia Giorgio, read a statement on behalf of her son Grant Dansie, saying he hoped sentencing sends a message.
"We hope this sends a message about protecting the rights of the most vulnerable," she said.
"At the same time we hope to see a thorough review of how the Government deals with the rights of the most vulnerable to fill the gaping holes in the system that's meant to protect them."
Her cousin, Grant Battersby, said the sentence "should serve as a deterrent and a warning to others like Peter Dansie whose toxic ego thought that they could just dispose of people who become a financial burden to them".
"Peter Dansie carefully, coldly, callously planned Helen's murder over weeks and months," Mr Battersby said.
"He probably didn't expect to be caught and punished.
"The appeal he lodged on Monday shows that he still doesn't accept his own guilt or show any remorse."
