Perth man Nicolau Soares believed killing his mother and stepfather was his only solution amid his fears he would be forced to take medication and be sent back to a psychiatric unit, a Hobart jury was told this morning.
Tasmanian forensic mental health services clinical director Michael Jordan told the jury in the double murder trial that Mr Soares' over-riding, delusional ambition was to join the Australian army's special forces and he was "prepared to kill" to make sure he could continue on his pathway.
Dr Jordan told the Tasmanian Supreme Court that as far as Mr Soares was concerned, he had to get the killing done.
He said in the hours before he bludgeoned to death former WA academics Del Weston and Gavin Mooney, he decided how the killing would be done and that he would use a hammer and block buster he had seen in the garage while working in the garden.
"This was a means to an end and had to be done," Dr Jordan told the jury of seven women and five men.
"He decided to attack them while they were together. He decided to attack them when they were unawares."
Mr Soares does not deny using the hammer and block buster to inflict the catastrophic and fatal head injuries that claimed the lives of his mother and stepfather at their isolated Mountain River property on December 18, 2012.
But Mr Soares, who has long battled the symptoms of schizophrenia, has pleaded not guilty to two counts of murder on the grounds of insanity.
Dr Jordan told the court this morning that Mr Soares had described performing the killings as quickly as he possible could.
He initially attacked them with the claw hammer, striking alternate blows to each of the retired academics until the metal head broke from its wooden handle.
Dr Jordan said Mr Soares was then compelled to return to the garage and get the block buster.
"He wanted to be determined that he had reached his goal to kill them," he said.
Under the paranoid belief that everything he was doing was being watched, he remained with the bodies for 24 hours while waiting to be "whisked away" to training with the special forces.
Dr Jordan outlined the history of Mr Soares' mental illness, telling the court that the 29-year-old had first shown signs of psychosis in 2006.
He said by 2007, Mr Soares began believing his parents, government agencies and bikies were among those who were "after him".
The beliefs recurred in ensuing years and Mr Soares also developed a conviction that some kind of apocalypse was imminent.
Dr Jordan said Mr Soares believed he had the skills to join a special forces unit with the army, which would equip him to deal with those working against him and any apocalypse.
He concealed his symptoms and his non-compliance with taking his medication, which he believed was poisoning him and he once described as "agent orange".
Dr Jordan said after Mr Soares was released from his third involuntary admission to Fremantle's Alma Street clinic, he remained on a community treatment order which legally mandated his taking of medication until late 2011.
But when the order lapsed and in the months before the deaths, he gradually stopped taking the anti-psychotic medication.
Dr Jordan said Mr Soares overheard his mother and stepfather calling a pharmacy to discuss filling a prescription for his medication on the afternoon of the killings.
Believing they would force him to take the medication and have him admitted to psychiatric care, which he thought would disqualify him from joining the special forces, he felt trapped.
"From that point, he decided the only way he could not be admitted to the psychiatric unit was by killing his mother and stepfather," said Dr Jordan, who agreed Mr Soares had been in the grips of a psychotic episode.
Dr Jordan said he initially assessed Mr Soares in March last year and formed the opinion he was unfit to stand trial as he would not have been able to understand the court proceedings.
By the middle of last year, after medication and treatment, he was of the opinion Mr Soares was fit to stand trial.
Outside court today, brother Alexander Soares reiterated the family's support for Nicolau.
"My sister Kathryn Weston and I wish to express in unequivocal terms that in the context of grieving the loss of our beloved parents...we also love and support our brother Nic," Alexander Soares said.
The trial continues.