A Supreme Court justice has found a murder charge against a knife-wielding chemical bomber was proved, but the killer was not criminally responsible.
Zack Mavin, 26, stood trial in the Supreme Court for armed robbery and the murder of 54-year-old Robert "Bobby" Palmer in the Newcastle suburb of Shortland, New South Wales, in December 2020.
He pleaded not guilty to murder and not guilty to attempted robbery with an offensive weapon.
Both the Crown and defence agreed that Mavin has schizophrenia or a schizoaffective disorder.
The primary dispute was about the impact the condition had on Mavin's state of mind on the night.
Justice Stephen Campbell presided over the judge-only trial.
On Tuesday, while delivering his judgement, he said the case hinged on whether defence barrister Paul Rosser KC had established a mental health impairment defence.
"It's whether the accused was able to appreciate the wrongfulness of the particular acts he was doing at the time ," Justice Campbell said.
"If, through a disordered condition of mind, he could not reason about the matter, it may be said he could not know what he was doing was wrong."
Justice Campbell said the mental health impairment defence had been proved.
But he said it had also been proved that Mavin murdered Mr Palmer.
Special verdicts
Justice Campbell said when police arrived Mavin acted as though he had done nothing.
"He seemed unable to follow the simple demand to put down his knife until he was tasered," Justice Campbell said.
"His demeanour strongly suggested his actions [were] justified and I was struck by his complete failure to appreciate the gravity of the trouble he was in.
"I am satisfied mental health impairment defence has been made good."
He said that meant he would deliver special verdicts for the two charges.
"Attempting to rob a 7-Eleven service station at Shortland is proven, but Zack Mavin is not criminally responsible," Justice Campbell said.
"In the act of fatally stabbing Robert Palmer, it is proven, but Zack Mavin is not criminally responsible."
The judge referred Mavin to be dealt with by the New South Wales Mental Health Review Tribunal.
'Deluded belief'
Before handing down his special verdicts, Judge Campbell said Mavin threw a home made chemical bomb at a service station worker, causing a small fire, after failing to rob it.
The court was told a mixture of ammonium nitrate and caustic soda were blended to create an improvised explosive device.
Justice Campbell said Mavin told police he armed himself with the bomb because he did not want to use a gun.
"Instead of grabbing a gun and having to shoot a person in the head, I figured I could make that and it would defeat the purpose of having a gun and harming anyone," Justice Campbell quoted Mavin as saying.
After the failed robbery attempt, Mavin headed towards a second service station.
Justice Campbell said he was delusional and believed the puppy Robert Palmer was walking was a savage pit bull, as opposed to a small terrier.
"He believed it necessary defend himself against an attack of Mr Palmer and his savage dog, Henry, leading him to draw the knife in the deluded belief he had to protect himself," Justice Campbell said.
At this point the judge said Mavin faced off with Mr Palmer before stabbing him.
"He appeared to be taunting Mr Palmer by dancing a small jig," Justice Campbell said.
The court was told that, moments later, Mr Palmer yelled: "I've been stabbed."
He later died from a 19-centimetre knife wound.
Sisters grieve
Because Justice Campbell found Mavin's murder charge had been proved he said victim impact statements could be read to the court.
Mr Palmer has three sisters, whose names were suppressed to protect their privacy.
One of the sisters said the family would never stop grieving.
"It has been a state of shock and denial that our family could have the most heinous of crimes of taking someone's life occur to us," she said.
Another of the sisters said that "losing Bob as a victim of crime has sucked the joy out of our lives".
The third sister said her brother had dedicated his life to his beloved local Shortland Devils Rugby League club and that the first game of each season was dedicated to him.
"He was clubman of the year many times and Bob would never have believed such an honour bestowed upon him," she said.
Justice Campbell ordered Mavin be detained in a criminal mental health facility as a forensic patient until he was no longer a danger to himself or others.
