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Supreme Court 3 December 2025

R v Wheeldon

[2025] NSWSC 1456

Homicide
CRIMINAL LAW MURDER DEFENCE OF MENTAL ILLNESS

Citation: R v Wheeldon [2025] NSWSC 1456
Court: Supreme Court of New South Wales
Date: 3 December 2025
Judge: Fagan J

Background

The accused was charged with the murder of his father at Pilliga, a small town in north-western New South Wales, on 10 August 2023. The accused had been staying at his father's home for approximately three weeks before the killing, accompanied by his partner and their infant child. During that period, neighbours reported near-constant loud arguments between the accused and his partner, and the accused was using methylamphetamine heavily.

In the two days before the killing, the accused did not sleep or eat, spoke incessantly and at times to himself, threatened his partner, and prevented her from leaving the house. Eyewitness evidence described the accused throttling his father in the yard of the home. The father died as a result. The accused did not deny causing the death; his sole defence was mental health impairment under the relevant legislation.

The trial proceeded before Fagan J sitting alone, by consent of both the Crown and the accused, pursuant to s 132(1) of the Criminal Procedure Act 1986 (NSW).

  • Whether the accused had a "mental health impairment" within the meaning of s 4 of the Mental Health and Cognitive Impairment Forensic Provisions Act 2020 (NSW) at the time of the killing.
  • Whether that impairment had the effect, under s 28 of the same Act, that the accused either did not know the nature and quality of his acts, or could not reason with a moderate degree of sense and composure about whether his acts, as perceived by reasonable people, were wrong.
  • How to deal with two related summary charges (intimidation and resisting police) in light of the verdict on the murder charge.

Decision

Both psychiatric experts, Dr Gerald Chew (retained by the accused) and Dr Kerri Eagle (retained by the Crown), gave evidence and were in agreement on the central questions. Both concluded that the accused was suffering from a schizophrenia spectrum illness and that this constituted a mental health impairment within the meaning of s 4 of the Act at the time of the killing. The expert opinions were unanimous, and Fagan J accepted them.

On the critical question under s 28, both experts were also in agreement that the accused's mental health impairment meant he could not reason with a moderate degree of sense and composure about whether his acts, as perceived by reasonable people, were wrong. This is the statutory formulation of the "did not know the act was wrong" limb of the mental illness defence. The defence was therefore established on the balance of probabilities, as required by s 28(2).

Fagan J noted his awareness of the matters in s 29 of the Act, which requires the judge in a jury trial to explain the possible verdicts and their consequences. Sitting alone, his Honour confirmed he would not be influenced by the consequences of a special verdict in reaching his conclusion. The verdict returned was not guilty by reason of mental illness.

On the two summary charges (intimidating the accused's partner and resisting a police officer), Fagan J considered it most appropriate to dismiss those charges and discharge the accused unconditionally under s 14(1)(c) of the Act, given that the accused would in any event be subject to ongoing detention and supervision by the Mental Health Review Tribunal.

Orders Made

  • The accused is to be detained at Long Bay Hospital, Malabar, or such other place as the Mental Health Review Tribunal determines, until released by due process of law (ss 33 and 34 of the Mental Health and Cognitive Impairment Forensic Provisions Act 2020).
  • The accused is referred to the Mental Health Review Tribunal (s 34).
  • The Registrar is directed to notify the Minister for Health, the Mental Health Review Tribunal, and Justice Health of the verdict and orders within 7 days, providing each with copies of the reasons, exhibits, and victim impact statements.
  • The charge of intimidating Danielle Newman with intent to cause fear of physical or mental harm is dismissed and the accused discharged unconditionally.
  • The charge of resisting Senior Constable Stephen Cruickshank in the execution of his duty is dismissed and the accused discharged unconditionally.

Key Takeaways

  • Where both the defence and Crown psychiatric experts are in agreement that an accused suffered a mental health impairment and could not reason with a moderate degree of sense and composure about the wrongfulness of their acts, the s 28 defence under the Mental Health and Cognitive Impairment Forensic Provisions Act 2020 (NSW) is established on the balance of probabilities.
  • A schizophrenia spectrum illness can constitute a "psychotic disorder" qualifying as a mental health impairment under s 4 of the Act, provided it produces the relevant disturbance of thought, mood, volition, perception or memory that impairs judgment or behaviour.
  • The statutory defence under s 28 is available even where an accused's mental state arises in the context of heavy substance use, so long as the impairment is not caused solely by the temporary effect of ingesting a substance or a substance use disorder: the distinction between a pre-existing psychiatric condition and acute intoxication remains important.
  • In a judge-alone trial, the factual question under s 28 is determined by the judge on the balance of probabilities; Fagan J confirmed that, in accordance with s 29(e), the consequences of a special verdict do not bear on the finding of guilt or innocence.
  • Following a verdict of not guilty by reason of mental illness, related summary charges can appropriately be dismissed and the accused discharged unconditionally under s 14(1)(c) of the Act where the accused will in any event be subject to ongoing detention and supervision by the Mental Health Review Tribunal.

Legislation and Cases Referenced

Legislation:
- Mental Health and Cognitive Impairment Forensic Provisions Act 2020 (NSW), ss 4, 14, 28, 29, 33, 34
- Criminal Procedure Act 1986 (NSW), s 132(1)
- Crimes Act 1900 (NSW)
- Crimes (Domestic Violence) Act 2007 (NSW)

Cases cited: No cases were cited in the material provided.