Gabriel Yad-Elohim stomped a pensioner to death just three days after being discharged from Auckland Hospital's mental health unit.

Today, the jury dismissed his defence of insanity and found him guilty of the murder of Michael Mulholland, 69, in September last year.

Yad-Elohim had a blank look on his face and stared straight ahead as the unanimous verdict was read out.

He had a history of mental health problems, having visited four mental health units in eight years, including his time inside Auckland's Te Whetu Tawera shortly before the killing.

Medical staff knew he took methamphetamine - there were traces of the class A drug in a urine sample he gave. But they could not force him to get help for his drug use.

Photo: RNZ / Dan Cook

When the hospital became full, Yad-Elohim was discharged to a community respite centre. He left his medication there and made his way to Karangahape Rd where he went looking for drugs.

But the case came down to the state of Yad-Elohim's mental health at the time of the killing. Essentially, the jury had to decide between two experts.

The Crown's psychiatrist, Peter Dean, acknowledged Yad-Elohim's history of schizophrenia.

But he said Yad-Elohim had been ripped off in a drug deal. He had given a woman $200 to get methamphetamine from Mr Mulholland and the woman had run off.

Dr Dean said despite his history of mental health issues, Yad-Elohim felt betrayed and angry when he was ripped off in a drug deal.

Yad-Elohim's lawyers called their own psychiatry expert, James Cavney. Dr Cavney concluded Yad-Elohim was hearing voices before the attack and even during the attack.

He said Yad-Elohim believed he was a messenger of God.

The day after the attack he was arrested by the police. The DVD recording of his police interview shows him turning to the empty corner of the room and holding up his cup as if he is toasting someone. There was no one there.

At the end of the recording the police left the room and Yad-Elohim appears to be talking to the spirit of Mr Mulholland.

But the Crown argued that Yad-Elohim acted out of revenge for being ripped off.

The Crown prosecutor Kirsten Lummis said Yad-Elohim set out to put Mr Mulholland in hospital for a long time.

She said it was significant Yad-Elohim headed back to Karangahape Rd after the attack to get methamphetamine.

Yad-Elohim has been remanded to Auckland's secure psychiatric unit, the Mason Clinic.

He's due to be sentenced next month.

The coroner can choose to hold an inquest into a violent or sudden death. The coroner can also make comments or recommendations in their finding to help prevent similar deaths in the future.

A spokesperson for the coroner said a decision on whether an inquest into Mr Mulholland's death would take place has not yet been made.