Murder accused Geoffrey Gordon Adams told police that "nice guys get pushed to the limits" during his confession to killing his wife almost 45 years after the 1973 crime, a South Australian Supreme Court jury has been told.
The 72-year-old has pleaded guilty to manslaughter but not guilty to murdering his wife Colleen at Maitland, on SA's Yorke Peninsula, in November 1973.
"It's alleged the murder was committed inside the family home at Maitland. It's alleged he killed Mrs Adams by hitting her in the head with a metal bar," prosecutor Jim Pearce QC told the jury during his opening address.
"After killing his wife, the accused went about concealing his crime. Within a few hours, he'd dug a shallow grave in the backyard of their matrimonial home and he buried Mrs Adams's body.
"He then went about setting a false trail — a trail designed to conceal his guilt."
Mr Pearce said the accused was interviewed by police in 1974, 1979 and 1980 and each time, Adams told officers his wife left him and their daughters, both aged under three.
"In essence, he was saying she left because she didn't like her lifestyle," he told the jury.
"The accused would subsequently tell police that Mrs Adams left the matrimonial home because she could not cope with her two children.
"He told police that when Mrs Adams left, she paused to say goodbye to her two little girls. He told police that Mrs Adams said to them, 'goodbye, you little bastards'."
Mr Pearce said the accused divorced his wife in 1977 before the disappearance was declared a major crime in 1979.
The jury was also told that in 1999, police used ground penetrating radar over a slab of concrete that was poured in the backyard of the Adams' family home but it found nothing.
Accused confessed after article published, court told
Mr Pearce said in September 2018, police released information to a newspaper which prompted the media to "camp outside" the Maitland house, and Adams's house in Wallaroo.
"On the prosecution case, the pressure was mounting," he said.
The court was told three days after the article about Mrs Adams's disappearance was published, the accused confessed to killing his wife.
"He told police, 'nice guys get pushed to the limit' and 'it's hard living with someone who lives with post-natal depression — they're at you, at you, at you'," Mr Pearce said.
He said Adams told police that "one night it just got bad — one hard hit or something and then if affects the rest of your life".
The court also heard that the 1999 dig at the property had been focused on the right spot, but did not go deep enough to find her.
Bill Boucaut QC, for Adams, told the jury that there was not much in dispute, describing his client's lies as "despicable" and his treatment of her body as "disrespectful".
But he said that did not mean he was guilty of murder.
The trial is expected to go for seven days.
