Police investigating the disappearance of Corryn Rayney in 2007 believed lies told by her husband led to potentially incriminating evidence being lost, the Supreme Court was told yesterday.
Prosecutor John Agius said that the day after Corryn Rayney went missing on August 7, 2007, Lloyd Rayney misled police about whether their home security alarm had recorded being switched on and off.
Mr Agius said detectives did not test Mr Rayney's honesty because of who he was.
"He said he was currently having some problems with the alarm system and it wasn't working," he said.
"The police accepted the explanation as well they might have at the time, the accused being a barrister and former prosecutor.
"In fact, the security alarm was working."
Mr Agius said the prosecution believed Mr Rayney would have activated and deactivated his alarm system when he left his sleeping daughters the previous night to bury his wife's body in King's Park.
"There is no other reason he would have lied (other than) he did not want police to be probing his computer," he said.
Mr Agius said that by the time the police checked the alarm system, after Mrs Rayney's body was discovered a week later, any record from the night she disappeared had been erased.
Mr Agius claimed yesterday that the alleged lie was one of many told by Mr Rayney to cover his tracks, forming the "consciousness of guilt" platform of the prosecution case of wilful murder.
He claimed Mr Rayney told lies to explain how a dinner party place card bearing his name came to be found in Kings Park, near the gravesite, before his wife's body was found.
The card had come from a law chambers dinner two weekends earlier, while Mrs Rayney and their daughters were in Melbourne.
"He told a colleague that he had driven to the chambers dinner in his wife's car," Mr Agius said.
He said that two other colleagues would testify that they "caught a lift" home from the dinner in a car similar to Mr Rayney's, not his wife's.
He claimed Mr Rayney also explained the place card to colleagues by claiming he was being deliberately set up for murder.
Mr Agius alleged that Mr Rayney made up stories of how his wife may have run away as he panicked because his "plan of near-perfection" had gone wrong when he damaged her car when disposing of her body.
He said Mr Rayney insinuated that his wife had a mental illness, even though she had no such medical history.
Mr Rayney told his sister-in-law, Sharon Coutinho, that he had called Mrs Rayney's divorce lawyer Gillian Anderson, who told him "he should check the Perth Clinic in case Corryn had had a mental breakdown".
"Yet Gillian Anderson denies ever having said that to the accused," Mr Agius said.
Mr Agius claimed that as part of his "subterfuge", Mr Rayney also tried to explain his wife's disappearance by claiming that "she had been put up to leaving by her friends".
He said that having listened covertly to Mrs Rayney's phone calls, he knew that she would never have left her daughters to run away.
Mr Agius claimed that Mr Rayney bolstered his story that his wife had run away by pointing out that her passport and purse were gone.
"He had moved the passport in the same way that he put her purse in her car - so that she would be missing," he said.
"His was all part of some concerted plan on his part to prove that she had voluntarily absented herself."
Mr Agius said that after Mr Rayney got to work on the morning after Mrs Rayney was allegedly murdered, he sent a "self-serving" email claiming to not know where she was. "I've left two messages," the email said.
"I didn't know why you left for work early and neither did the girls."
Mr Agius said there was evidence Mrs Rayney never went to work early and her husband knew she would not have.
The court was told that after the body was found buried with a handkerchief under her head, police questioned Mr Rayney and Caitlyn and Sarah about whether it might belong to Mrs Rayney.
"There came a reply from both of the girls that she hated them (handkerchiefs)," he said.
"The accused went into the bedroom and brought out some handkerchiefs.
"When he was questioned again, he reiterated that his wife did use handkerchiefs."