On March 3 last year, Sydney man Adam Brewer said he wanted to lay down on train tracks and die and he would "stab, fight and kill" anyone who came near him.
On March 11 he was discharged from a Sydney mental health hospital.
Two days later he fatally stabbed real estate agent Vissa Esan.
Brewer, 33, was found not guilty of murder on the basis of mental illness on Friday, after he stabbed Mr Esan outside the Pendle Hill real estate agency where the 47-year-old worked in Sydney's west on March 13, 2014.
Brewer had not raised mental illness at his judge-alone trial, arguing instead that he acted in self-defence.
His barrister Peter Skinner had told the NSW Supreme Court he was bound in that regard but if mental illness was to be raised as a result of the evidence, he would not attack it.
Brewer, the trial had heard, had a long history of mental illness and poly-substance abuse.
In January 2012, while in custody for a break and enter, Brewer fashioned a noose out of his underwear.
Two years later in January 2014, he told police he was going to "end it".
Then on March 3, just 10 days before Mr Esan's death, Brewer was spotted going into a TAFE with bolt cutters. He was then seen standing at a white board, talking to himself and pretending to be a teacher.
Later that afternoon he went into Blacktown Centrelink office and told staff he wanted to "lay on train tracks and die" and he would "stab, fight and kill anyone who came near him", Justice Geoffrey Bellew noted.
He was discharged from Cumberland psychiatric hospital at Westmead in Sydney's west on March 11.
Justice Bellew found Brewer was suffering from a psychotic disorder when he stabbed Mr Esan following a fight between the pair at his agency and a neighbouring arcade.
"(This) resulted in him now knowing what he was doing was wrong."
In handing down his decision, Justice Bellew said he was conscious of the fact Mr Esan's family "suffered a sudden and indescribably loss" on March 13 and hoped the proceedings brought some closure for them.
Outside court Ms Esan's widow, Shanika Dona, said "What can I do, I lost my husband?"
Speaking of their one-year-old son, she told reporters: "I got a beautiful boy from him to remember his face so I see him through my son."
Brewer will be detained under the Mental Health Act.
* Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14 or the Suicide Call Back Service 1300 659 467.
