An Adelaide man has been found guilty of murdering his wife by pushing her wheelchair into a pond, after a court heard she had allegedly become a burden to him.
Peter Rex Dansie, 70, was charged with the murder of 67-year-old Helen Dansie at Veale Gardens in Adelaide's parklands in April 2017.
Justice David Lovell delivered his verdict after the trial wrapped up in late October.
During the trial, prosecutors alleged Dansie murdered his wife by drowning her in the pond because she had become a cost burden.
In his reasons for the verdict, Justice Lovell said in his view, the prosecution had 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.
"While the existence of such a motive does not of itself establish that Mr Dansie is guilty of murder, it falls to be considered with the balance of the circumstantial evidence relied upon by the prosecution," he said.
Justice Lovell said he took all the evidence into account and found the prosecution had proved beyond a reasonable doubt that Dansie committed acts that were "voluntary, conscious and deliberate" by pushing his wife into the pond.
"The act or acts committed by Mr Dansie caused the death of Mrs Dansie," he said.
"At the time, Mr Dansie committed the act which caused the death of Mrs Dansie, Mr Dansie had a specific intention to kill Mrs Dansie.
"The act which caused the death of Mrs Dansie was unlawful."
The prosecution previously said Mr Dansie had been engaged in "steamy" online chats with two Chinese women and was ready to fly to China with a bag of sex toys and condoms about a month after his wife died.
Victim fell through 'gaping holes in the system'
Dansie's son, Grant Dansie read out a statement following the verdict, saying he was pleased justice had been served.
"Mum was a truly amazing person, she was funny, smart and she had a huge heart," he said.
"Her murder was a tragedy and we miss her every day. I'm glad that we've achieved justice."
While he thanked police for their work on the case, he said his mother's death was avoidable.
"The greed, callousness and lack of humanity was despicable and I'm very satisfied with the verdict today," he said.
"My beautiful mother belonged to three vulnerable groups — she had a disability, she was elderly, and she was a victim of domestic violence.
"Yet she managed to fall through all of the supposed safety nets, this isn't good enough.
"She didn't just fall through a crack, she fell through gaping holes in the system."
Dansie regarded wife as 'cost burden', court told
Opening the prosecution's case earlier this year, Jim Pearce QC told the court that Dansie thought his wife had become a "burden" to him.
"On the prosecution case she was thrown into the pond by the accused," Mr Pearce said.
He previously described the case as a "premeditated killing" with a "financial motive".
"Helen Dansie had become a cost burden on the accused, it was a cost burden he was no longer prepared to tolerate," Mr Pearce said.
The court previously heard 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 heard.
It heard family members and friends had expressed concerns about Mrs Dansie's level of care and her husband was reluctant to spend money on basic healthcare for her.
