Halls Head murderer Damian Eric Maxfield (40) was suffering from meth induced psychosis when he stabbed Scott Martin to death

Damian Eric Maxfield.
Damian Eric Maxfield.

A man who broke into an apartment in Mandurah murdered a resident and attacked his partner had been on a five-day methylamphetamine bender and was in a psychotic state, a court heard on Thursday.

On the day he was due to stand trial earlier this week, Damian Eric Maxfield, 40, admitted stabbing 40-year-old Scott Martin as he slept and attacking his partner Erelle Mason, 32, in their Halls Head home in January last year.

During sentencing submissions in the Supreme Court of WA on Thursday, it emerged Maxfield had been a long-term meth user and had also drank alcohol and gone to the casino before getting into the secure apartment building.

Prosecutor Laura Christian said Maxfield launched “an unprovoked attack on a complete stranger while he was asleep”, then used various objects to hit Ms Mason, inflicting serious injuries.

He choked her twice as she fought back and she started to lose consciousness more than once, Ms Christian said.

Ms Mason’s fortitude prevented her from being killed, the prosecutor said.

She ran out of the unit and Maxfield tried to coax her back inside.

As Mr Martin lay dying, Maxfield took a laptop computer that was next to him and had Mr Martin’s blood on it and left by climbing down from the 10th-floor balcony to the level below.

Defence counsel Paul Yovich submitted his client had acted irrationally as he had an underlying delusional disorder – believing the Russian mafia was coming after him – and that was exacerbated by his heavy drug use.

Mr Yovich also said Maxfield had no memory whatsoever of what happened and was genuinely remorseful.

But Ms Christian read out a personal phone conversation Maxfield had in jail in which he said: “I don’t know if I should say I don’t remember much or just spill the beans”.

She urged Justice Michael Corboy to reject psychiatric diagnoses of Maxfield having some sort of underlying disorder, saying “his condition at the time was entirely drug-induced”.

Justice Corboy asked Ms Christian if he should view the crimes as “a horrific, violent act with no explanation, without motive”.

She agreed although Maxfield had become obsessed with the belief his guitar was in the apartment.

Maxfield will be sentenced in September.