Citation: R v Villalon [2014] NSWSC 725
Court: Supreme Court of New South Wales
Date: 23 May 2014
Judge: Price J
Background
The accused faced a murder charge arising from the killing of the deceased. The defence raised the partial defence of substantial impairment by abnormality of mind, which under New South Wales law can reduce a murder conviction to manslaughter. The onus of establishing that partial defence rested on the accused on the balance of probabilities.
The accused's case centred on the proposition that, at the time of the killing, he was in the prodromal (early, pre-diagnosis) stage of untreated paranoid schizophrenia. Three forensic psychiatrists were anticipated to give evidence to that effect.
The disputed question was whether those psychiatrists could also present research-based evidence that individuals in an untreated first episode of psychosis face a significantly elevated risk of irrational violence. The Crown objected to that component of the proposed expert evidence.
Legal Issues
- Whether the proposed research-based evidence about violence risk in untreated first-episode psychosis was relevant under s 55 of the Evidence Act 1995 (NSW).
- Whether that evidence constituted impermissible tendency evidence under s 97 of the Evidence Act 1995 (NSW).
- Whether the evidence should be excluded under s 135 of the Evidence Act 1995 (NSW) on the basis that its probative value was substantially outweighed by the danger of unfair prejudice, misleading or confusing the jury, or undue waste of time.
Decision
The Crown argued that the proposed evidence was statistical in nature and invited the jury to reason that, because the accused committed a violent act, earlier irrational behaviour should retrospectively be interpreted as psychotic symptoms. The Crown characterised this as "reasoning backwards" and as a form of tendency reasoning: that people with the accused's symptoms have a higher propensity for violence.
Price J rejected both contentions. His Honour found that the evidence could rationally explain, in expert psychiatric terms, the reduced understanding, insight, and self-control more likely to be experienced by a person in an untreated prodromal psychotic state compared to a treated patient or a person without the illness. That made it directly relevant to the two core facts in issue: whether the accused's capacity to understand events, judge right from wrong, or control himself was substantially impaired; and whether that impairment was sufficiently substantial to reduce liability from murder to manslaughter.
On the tendency evidence objection, the Court found that the proposed evidence did not concern the character, reputation, or conduct of the accused, nor any tendency the accused personally had or had had. Rather, it was generic research evidence applicable to a defined class of persons, drawing on published meta-analyses. Price J compared it to pharmacological evidence routinely given by experts about the behavioural effects of alcohol on intoxicated persons generally.
Turning to s 135, the Court found no basis to exclude the evidence. Its probative value on a core issue was significant, the Crown had been served with the relevant reports and research papers in advance, and the evidence was neither unfairly prejudicial, misleading nor confusing, nor likely to cause undue waste of time.
Orders Made
• The court admits the anticipated evidence of Dr Westmore and Dr Furst regarding increased risk of irrational violence during the untreated prodromal stage of psychiatric illness.
Key Takeaways
- Research-based psychiatric evidence about the elevated homicide and violence risk during untreated first-episode psychosis was held to be relevant under s 55 of the Evidence Act 1995 (NSW) where substantial impairment was a live issue at trial.
- The distinction between generic population-level research and evidence about a specific accused's personal tendencies was central: evidence derived from published studies about a class of persons does not constitute tendency evidence within the meaning of s 97 of the Evidence Act 1995 (NSW).
- A useful analogy emerged from the judgment: expert evidence about the general behavioural effects of untreated psychosis on a class of persons is comparable to pharmacological evidence about how alcohol affects intoxicated people, both being grounded in research rather than individual assessment.
- Under s 135, evidence of significant probative value to a core defence issue will not readily be excluded for unfair prejudice, particularly where the opposing party has had reasonable opportunity to respond to the material.
- Qualified forensic psychiatrists may present and comment on peer-reviewed research findings within their field of specialised knowledge under s 97 of the Evidence Act, even where the lead researcher is not personally called to give evidence.
Legislation and Cases Referenced
Legislation:
- Evidence Act 1995 (NSW), ss 55, 97, 135
Research Papers Referenced in the Judgment:
- Nielssen, Ryan, Large and Hayes, "Legal implications of the increased risk of homicide and serious violence in the first episode of psychotic illness"
- Nielssen and Large, "Rates of homicide during the first episode of psychosis and after treatment: a systematic review and meta-analysis" (2010) Schizophrenia Bulletin 36, pp 706-712