A forensic scientist said today he was unable to give a definitive opinion about murder accused Antonie Dixon's mental state, but his "fluctuating behaviour" was consistent with mental disorder.
Dr Justin Barry-Walsh was giving defence evidence in the High Court at Auckland where Dixon is on trial on eight charges including murdering James Te Aute and causing grievous bodily harm to Renee Gunbie and Simmone Butler.
Dixon is accused of shooting dead Mr Te Aute in Auckland after attacking the two women with a samurai sword near Thames in January 2003.
Dixon was found guilty of all the charges in 2005 but the Court of Appeal later ordered a second trial, suppressing its reasons for quashing the convictions.
Dr Barry-Walsh told the jury Dixon had a life-long dysfunctional personality and the use of methamphetamine had aggravated his personality disorders.
He said Dixon sometimes feigned symptoms in an attempt to mislead people over the state of his mental health because he believed it would mean avoiding prison.
Dixon's personality disorders, which were not a disease of the mind, combined with likely heavy methamphetamine use, made it difficult to give an accurate assessment of his mental health.
Yesterday Dixon's sister Carla Dixon-Foxley told the court how her younger brother was physically and emotionally abused by their devout Jehovah's Witness mother.
Dixon grew up hearing his mother quoting biblical verse and references to demons and the chosen ones.
Dr Barry-Walsh had two meetings with Dixon in 2005 and observed him giving evidence during the first trial.
Some of Dixon's behaviour, both during assessments when he spoke of seeing goblins and hearing God, and during the trial, had a "theatrical quality", he said.
Under cross-examination by the Crown, Dr Barry-Walsh said any assessment he made was in part dependent on the truthfulness of the patient.
Dixon talked of a conspiracy against him involving the police.
"Mr Dixon was repeatedly at pains that it was his opinion that the conspiracy continued."
Dixon did suffer from personality disorders which complicated the assessment, he said.
Dixon also appeared to have been a heavy methamphetamine user which Dr Barry-Walsh admitted could have contributed more to his actions that even than his mental health.
Dixon has admitted using P occasionally but has denied being a heavy user.
Dr Barry-Walsh said it was likely P would exaggerate any ideas Dixon already had.
Crown prosecutor Richard Marchant asked if Dixon had a manipulative personality.
"Manipulation seems to be a feature of his personality, yes."
Mr Marchant asked why Dixon would be making some of the symptoms up.
"I find that hard to answer."
Dixon felt it was in his best interests to exaggerate and to feign symptoms to escape conviction, he said.
"Equally it doesn't help (Dixon) at all."
Dr Barry-Walsh said a picture had emerged of an impulsive, overactive man who lacked in judgment and could not help but shoot his mouth off sometimes.
The trial adjourned at lunchtime today and continues tomorrow.
