ROBERT Penny was initially ruled out as a suspect in the murders of his wife and her hairdresser because the crime seemed too brazen and violent for the retiree to have committed.
But detectives now suspect Penny might have been motivated to kill his 58-year-old spouse because he was having an affair with a young woman who became his second wife.
Margaret Penny and her hairdresser Claire Acocks, 49, were found beaten and stabbed to death at the Old London Coiffure hairdressers in the western Victorian town of Portland in May 1991.
"It didn't fit for me in that initial phase that Bob Penny could do that particular crime," Detective Rodney Graham Wilson told a second inquest into the unsolved murders on Monday.
Penny told police at the time that he had been playing in the backyard with his granddaughter when his wife had gone into town for her regular 2pm hair colour appointment.
A couple of hours later, she and Ms Acocks were discovered in a back room of the salon with multiple stab wounds to their neck, back and abdomen. Aside from the extreme violence, which Detective Wilson did not think Penny capable of, cash from the till and the women's credit cards had been stolen, leading investigators to think the culprit was an "opportunistic thief".
"But homicide inquiries are a long-term game," Detective Wilson said.
"Things are going to unpack along the way."
Penny was charged over the murders in 2015 after new evidence came to light, but he died last year aged 83 before facing a committal hearing.
At the time of the killings, he told his children and Ms Acocks' family that a tail comb had been used in the attacks, the inquest last November heard.
On Monday, the Coroners Court of Victoria heard Penny was rumoured to have been having an affair at the time of the double murder.
"The marriage between Margaret and Bob was not as it may have appeared initially," Detective Wilson said.
Penny had a history of unfaithfulness he said, which "may lead in some way to a motive".
"Then we have got the infidelity with (second wife) Kim," he said.
It was more likely Penny would have contracted someone to carry out the killing, rather than do it himself, the detective said.
Inspector Martin Allison, who also worked on the case in its early years, said he was unaware of any marital unfaithfulness.
But he said Penny had married Kim after a six-week courtship soon after losing his wife.
"We thought that it was particularly odd, and I remember having a conversation with Kim Penny about that," Inspector Allison said.
The second wife of a man suspected of killing his first wife and her hairdresser in Victoria will give evidence at the inquest into their unsolved murders on Tuesday.
It was information that did not come from any of the witnesses at the scene at the time.