Given a positive family history of depression and psychosis, he was genetically vulnerable to developing a serious mental illness. He was brought up in an environment characterised by domestic violence and aggression. His scholastic trajectory was compromised by behaviour problems and attention deficit hyperactivity disorder, leaving school in year eight. Further compromising his development and aggravating his genetic vulnerability has been the early onset of substance use. He has since had limited capacity [for] employment and committed relationships. His psychosocial course has been complicated [by] multiple admissions to psychiatric hospitals. Earlier diagnostic formulations considered his behavioural problems as stemming from a combination of substance use, ADHD and antisocial personality. There have been however sustained reports of psychotic symptoms dating back to at least 2000. Over time the diagnostic formulations has evolved to a diagnosis of schizophrenia. I note that he has been diagnosed with antisocial personality disorder, however in an individual who is recurrently experiencing psychotic episodes in the context of substance abuse, it would be difficult to confirm such a diagnosis until he has been monitored in the absence of substance abuse and psychotic symptoms.
In the time leading up to the alleged offence he was utilising substance including heroin, methamphetamine lines and cannabis. He was using methamphetamine lines intravenously in the context of difficulties in his relationship with his girlfriend. The methamphetamine would have had the effect of aggravating his symptoms of schizophrenia at the time.
By the time of the alleged offence he reported experiencing auditory hallucinations and ideas of reference as well as persecutory beliefs.
He stated that the complainant was making threats to kill and have anal sex with him and that the complainant actually took his tools. These appear to be the two most significant beliefs that motivated the alleged offending reported by him.
There is factual evidence that the complainant threatened him in the manner he claims and made phone calls to him. Whether he stole his tools is unclear. I would on balance accept that the belief that the complainant was going to kill him and have anal sex with him was base[d] on a relatively rational interpretation of events.
Whether or not the complainant took his tools in fact, or the tools were simply mislaid, or he had a delusional belief that the complainant stole it is unclear to me. I think it unlikely that the belief that he had tools was delusional but cannot rule this out definitively.
Based on the information provided, there are reasonable grounds to conclude [he] was experiencing that is psychosis [sic], secondary to aggravation of his schizophrenic illness and thus psychotic symptoms with the use of substances.
I do not however believe that he would have available to him a defence of mental impairment.
It would nevertheless be reasonable to view the psychosis would have exaggerated the threat the complainant posed to him. That is, that even if the real threats were made, the psychosis compounded the belief from one, which he might have held with a degree of scepticism (if he had not been psychotic) to one he held with greater conviction. So that with contribution of his psychosis at effecting his judgement and disinhibiting him, he came to believe that a pre-emptive strike was necessary to protect himself from physical and sexual assault by the complainant.