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Supreme Court 9 July 2018

R v Griffiths

[2018] NSWSC 1116

Assault & violenceHomicide
CRIMINAL LAW EVIDENCE VOIR DIRE ADMISSIBILITY OF EVIDENCE

Citation: R v Griffiths [2018] NSWSC 1116
Court: Supreme Court of New South Wales
Date: 9 July 2018
Judge: Campbell J

Background

The accused was charged with the murder of a man who died on 30 September 2014 from traumatic brain injuries sustained when the accused struck him with his elbow. The accused had entered a plea of not guilty to murder but guilty to manslaughter, relying on the partial defence of substantial impairment by abnormality of mind under s 23A of the Crimes Act 1900 (NSW). That plea was not accepted by the Crown, and the matter proceeded to jury trial.

The accused had a longstanding diagnosis of schizophrenia and was on prescribed antipsychotic medication, as well as opiate and benzodiazepine medication for a separate condition, at the time of the offence. A forensic psychiatrist, Professor Greenberg, opined that the accused's capacity to control his actions was substantially impaired by an abnormality of mind arising from his schizophrenia.

Before the jury heard opening addresses, a voir dire (a pre-trial hearing to determine whether evidence is admissible) was conducted to determine whether two statements made by a witness, Ms Sharp, could be placed before the jury. Those statements recorded conversations she had with the accused after the offence.

  • Whether the representations in the first statement (in which the accused asked Ms Sharp to lie to police, and described the assault) were admissible as implied admissions or evidence of consciousness of guilt.
  • Whether the representations in the second statement (including the accused's remark that he "wasn't having a psychotic episode when it happened") were admissible, or whether the risk of jury misuse outweighed their probative value under s 137 of the Evidence Act 1995 (NSW).

Decision

Campbell J admitted the first statement in full. The accused's request for Ms Sharp to provide a false alibi, combined with his account of the assault, constituted an implied admission and was capable of serving as evidence of consciousness of guilt. The probative value of that material, particularly its relevance to the jury's assessment under R v Trotter (1993) 35 NSWLR 428 of whether the accused's impairment was sufficiently substantial to warrant a reduction from murder to manslaughter, outweighed any risk of unfair prejudice.

The second statement, however, was excluded under s 137 of the Evidence Act. The critical concern was the accused's statement that he "wasn't having a psychotic episode when it happened." His Honour found that a jury could impermissibly treat this lay remark as an admission that no relevant abnormality of mind existed, which would undermine the first limb of the substantial impairment defence. Whether the accused was experiencing a psychotic episode is a question requiring expert psychiatric evidence, not lay self-assessment.

Campbell J noted that both psychiatric experts were in agreement on the question of abnormality of mind, and that a patient's own characterisation of their mental state carries little weight against unified expert opinion. The risk that the jury would read more into the statement than it properly offered meant the risk of misuse, even if not great in absolute terms, exceeded the statement's probative value.

His Honour accordingly excluded the entirety of the second statement in exercise of the discretion conferred by s 137, having regard to s 192 of the Evidence Act.

Orders Made

  • The representations in the first statement (Exhibit Voir Dire 6) were admitted and permitted to go to the jury.
  • The representations in the second statement (Exhibit Voir Dire 7) were excluded in their entirety under s 137 of the Evidence Act 1995 (NSW).

Key Takeaways

  • Under s 137 of the Evidence Act 1995 (NSW), a court must exclude evidence in a criminal proceeding if the risk of unfair prejudice to the defendant outweighs its probative value, even where that risk is not considered substantial in absolute terms.
  • A defendant's lay remark about their own mental state, such as denying a psychotic episode, carries limited probative value where unified expert psychiatric evidence addresses the relevant question, because whether a person was experiencing psychotic symptoms is a matter within the exclusive domain of expert evidence.
  • R v Trotter (1993) 35 NSWLR 428 confirms that when a jury assesses whether impairment is "substantial" enough to reduce murder to manslaughter under s 23A of the Crimes Act 1900, it may consider all circumstances of the case, including the accused's conduct before, during, and after the killing, in addition to expert evidence.
  • The determination of whether an impairment is sufficiently substantial to warrant a reduction in criminal liability involves a value judgment for the jury, guided by community standards, rather than a finding of medical fact.
  • Exclusion of part of a witness's evidence does not necessarily require exclusion of the whole of that evidence: the Supreme Court admitted one statement while excluding the other, having assessed each on its own merits.

Legislation and Cases Referenced

Legislation:
- Crimes Act 1900 (NSW), s 23A (substantial impairment by abnormality of mind)
- Evidence Act 1995 (NSW), ss 137 (exclusion of prejudicial evidence in criminal proceedings), 192 (leave, permission or direction)

Cases:
- R v Trotter (1993) 35 NSWLR 428
- R v Baden-Clay (2016) 258 CLR 308; [2016] HCA 35
- R v White [1998] 2 SCR 72