A man who beat a West-Auckland man to death with a hammer in 2006 and had his conviction overturned has been found not guilty by reason of insanity.
David Francis Fa, 32, was sentenced to life in prison in 2007 for the brutal murder of 22-year-old Stuart Stone.
Stone, a print operator at Suburban Newspapers, had parked his car and was on his way to visit friends in Seaside Ave, Waterview, on January 27, 2006, when Fa attacked him from behind with a knife and hammer.
Fa took Stone's car, leaving the young man to die on the side of the road.
Police found the car at Fa's house but when they approached, Fa armed himself with two knives and lunged at them.
Fa was assessed by two psychiatrists before his trial. He was uncommunicative and one psychiatrist said he was unsure if Fa was fit to stand trial.
The other psychiatrist said Fa was fit, and he was found guilty of murder and two counts of assault following a week-long trial in 2007.
In sentencing Fa, Justice Rodney Hansen said: "Your thinking process in general and what drove you to commit this terrible crime remain a complete mystery.
"You simply brutally attacked a defenceless man for no reason other than to take his car."
Fa's psychiatric illness manifested itself with psychotic episodes, while he was in prison.
Clinicians determined that Fa had schizophrenia and treatment began.
The Court of Appeal overturned Fa's conviction in 2012, ruling that he had not been fit to stand trial in 2007.
Fa's treatment progressed to the point where he was judged fit to be re-tried but this time the extent of his illness was revealed.
Psychiatrist Dr David Chaplow told the High Court in Auckland today that Fa began suffering psychotic symptoms in his early 20s.
At the time of the killing, Fa was hearing voices, said he was receiving messages from the radio and telephone, and thought he was invincible and that he was under surveillance.
Fa told doctors that on the night of the killing he was going to rob a house but rather than take things, when the people in the house saw him they would leave and cede him ownership of the house.
The voices in his head said he had to kill a man and he would know who that man was when he saw him.
Justice Sarah Katz ruled that Fa was suffering a disease of the mind at the time of the killing and though he knew what he was doing, his illness meant he did not know his actions were morally wrong.
She found him not guilty by reason of insanity and ordered that he be detained as a special patient under the Mental Health (Compulsory Assessment and Treatment) Act.