A court has heard that while a man accused of killing his wife admits he was "playing around with other women and at times violent", that did not make him guilty of murder.
John Douglas Bowie, 72, has pleaded not guilty to killing his wife Roxlyn Bowie on or about June 5, 1982 when she disappeared from their home in Walgett, in north-west NSW.
She was 31 years old and left their two young children behind, then aged six and almost two. Her body has never been found.
In the defence's opening address, Senior Counsel Winston Terracini emphasised that the case against Mr Bowie was entirely circumstantial and witnesses could give testimony that places the accused in their company "nowhere near the family home or the piggery" on the night Roxlyn Bowie was allegedly murdered.
On Tuesday, the jury was told part of the Crown's case would be that Mr Bowie killed his wife to pursue an "unfettered, serious relationship" with a woman he met the month before and had started a sexual relationship with.
Mr Terracini said just because Mr Bowie had "low standards [as a husband] and even then had difficulty living up to them", it was important the jury remembered "that's not murder".
"We're not saying he's a perfect fellow in relation to his adultery and behaviour to his wife," he said.
"Sadly, you may know from your own experience … that people behave appallingly in domestic relationships, but that's a long way from murder."
Crown prosecutor Alex Morris foreshadowed evidence that, on six different occasions, Mr Bowie had said to colleagues: "If you ever want to get rid of anybody, feed them to wild pigs" and "pigs don't leave any evidence behind, including bone".
The Crown called its first witnesses including a friend of Ms Bowie's, Noleen Knight, who shared with the court that Ms Bowie told her the accused had been "playing around with other women" as recently as three days before her disappearance.
However, Ms Knight struggled at times to recall details including when she last saw Ms Bowie, if Ms Bowie had ever visited her Sydney home, and whether she had seen Mr Bowie at all after his wife disappeared.
Mr Morris read out extracts from previous statements Ms Knight had made to police in 1993 and 2018, as well as to the 2014 coronial inquest into Roxlyn Bowie's disappearance to help "refresh" her memory.
When presented with her sworn statements, Ms Knight reaffirmed their accuracy and said they would be more reliable than her current memory.
The court heard sections of a statement Ms Knight made to police on August 21, 1983.
"I received a call from John Bowie … he told me Roxlyn had left," it read. "He told me she had packed some things in a blue suitcase, which she had taken with her."
"My husband [Brian] spoke to John and sometime later Brian went up to Walgett and brought the children back [to Sydney] to stay with Roxlyn's parents.
"It seemed like a matter of days after Brian returned from Walgett with the children that John Bowie arrived, he stayed at our place for a couple of nights before he found accommodation.
"Whilst John Bowie was at our house I saw he had a blue suitcase. I took particular notice because in the phone call I had with him, he'd told me Roxlyn took a blue suitcase with her when she left."
The defence argued that Mr Bowie had been cooperative with police since his wife's disappearance, including making statements, taking part in a recorded interview, and "being cross-examined in the witness box by a lawyer assisting the coroner for a very long time" during the 2014 coronial inquest into Roxlyn's presumed murder.
The trial continues.
