Retired WA academics Del Weston and Gavin Mooney were eating dinner in the lounge room of their isolated Tasmanian property when their mentally ill son attacked them with tools from their garage and inflicted the catastrophic head injuries which caused their deaths, a Supreme Court jury was told in Hobart this morning.
In opening statements in the double murder trial of Nicolau Francisco Soares, both prosecutor Linda Mason and defence lawyer Rochelle Mainwaring described a tragic case which would hinge on the defence of insanity.
The jury was also told it would hear evidence of increasingly desperate attempts by Mr Soares' family to get him help after he was diagnosed with schizophrenia and unsuccessful bids by his mother and stepfather to get him medication right up until the afternoon before their deaths.
The jury was told that Mr Soares did not dispute that his actions had caused the deaths of Dr Weston and Professor Mooney at the couple's Mountain River home on the night on December 18, 2012.
Ms Mason said it was a "most horrific" killing and prosecutors alleged it had "all the hallmarks of being a premeditated killing" that was "executed with purpose".
She said Mr Soares, 29, had come from Perth to stay with his mother and stepfather two weeks before he attacked them with a hammer and block buster taken from among the gardening tools in the couple's garage.
The jury was told Mr Soares initially called 000 in the early hours of December 19, identifying himself as "Fred" and saying he needed to be picked up.
Ms Mason said Mr Soares remained in the house with his deceased mother and stepfather for a further 24 hours before again calling 000 on December 20.
He again identified himself as "Fred", said he had killed two people with a hammer and he was waiting to be arrested.
"On the face to it, it appears to be a clear-cut case of the intentional an unjustified killing of two human beings," Ms Mason said.
But she said the jury would hear of the tragedy of circumstances that led to the events that unfolded on the night of the deaths, including the lengths Mr Soares' family had taken to help him with his long-standing mental illness.
Ms Mason said the jury would hear evidence that Mr Soares' illness, which caused erratic, paranoid behaviour and led to him suffering delusions, had defined his way of life.
She said Mr Soares, who had been admitted as an involuntary patient numerous times in the years before the alleged murders, did not have a lot of insight into his mental illness.
Ms Mainwaring said there was only one issue in the trial, which was whether Mr Soares was so mentally unwell at the time of the killings that he could not be held criminally responsible on the ground of insanity.
She said a psychiatrist would be called to give evidence that in his opinion, the severity of Mr Saores' mental illness had deprived him of the capacity to understand that his acts were wrong and ones which he ought not to do.
In a written statement admitted in to evidence, Mr Soares' half-sister, Katherine Weston, a child of her mother's first marriage, described the family's efforts to get her sibling help after his behaviour changed in about 2008.
Ms Weston described her half-brother's early childhood as one of being exposed to violence at the hands Mr Soares's father, her mother's second husband, before the couple separated.
She said Mr Saores had been a talented musician and was accepted into training in gymnastics at the WA Institute of Sport as a child, but he became socially isolated as a teenager.
Ms Weston said Mr Soares had been admitted as an involuntary patient at the Alma Street clinic in Fremantle several times, but her mother felt frustrated and helpless that she could only get assistance when the situation with her son reached an acute crisis.
Earlier today, Justice David Porter warned the jury of seven women and five men that the trial would include graphic evidence which may be shocking and distressing.
Justice Porter said the evidence would include fairly graphic photographs and a video of the scene of the alleged crimes which contained images of the deceased bodies as they had been found.
The trial is scheduled to run for up to six days.