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Supreme Court 4 March 2019

R v Thomas Dillan Stone

[2019] NSWSC 195

Homicide
SENTENCE CRIMINAL LAW MURDER PLEA OF GUILTY

Citation: R v Thomas Dillan Stone [2019] NSWSC 195
Court: Supreme Court of New South Wales
Date: 4 March 2019
Judge(s): Hidden AJ

Background

The offender was a forensic patient detained at Morisset Hospital, having previously been found not guilty of serious charges by reason of mental illness in 2013. Over the years following that finding, his mental state appeared to improve steadily, and he had been transferred to medium-security accommodation, including self-contained cottage housing within the hospital grounds.

On 6 February 2017, the offender purchased a kitchen knife during an unsupervised outing to a nearby town. That evening, he entered the bedroom of a fellow patient and stabbed him three times. One wound to the neck proved fatal. The offender then walked to the lake shore, discarded the knife, and called emergency services to report that he had stabbed someone.

In subsequent psychiatric examination, the offender stated he had deliberately chosen a larger victim to prove himself, that he was calm and planned the attack, and that his motivation was to return to a prison environment rather than remain in hospital. He pleaded guilty to murder.

  • Whether the offender's mental illness had a causal connection to the offence, given the apparent absence of active psychotic symptoms at the time
  • Whether the offender's substantial impairment defence under section 23A of the Crimes Act 1900 was available and, if so, what weight to give it
  • Whether the offender presented a continuing danger to the community
  • The appropriate sentence, including the weight to give the guilty plea and whether special circumstances justified departing from the standard non-parole period proportion

Decision

Three forensic psychiatrists examined the offender. Their evidence established that the offender suffers from a longstanding schizophrenic illness with antisocial personality traits. However, at the time of the killing, he did not appear to be experiencing active psychotic symptoms such as hallucinations or delusions. His stated motivation was a rational, if deeply troubling, preference for prison over hospital detention.

The court found that, while the offender's underlying mental illness was a background factor, there was no sufficient causal link between an acute mental illness episode and the commission of the murder. The offender had formed a deliberate plan, purchased the murder weapon in advance, selected his victim, and acted in a premeditated way. The partial defence of substantial impairment was not available, and the offender abandoned it. His abandonment was consistent, the court noted, with his criminal purpose of committing a serious and obvious offence to attract a lengthy custodial term.

On the question of continuing danger, the court accepted that the offender posed a significant ongoing risk to the community, particularly within an institutional setting. This was a substantial aggravating factor. The offender's personal circumstances, including his mental illness and institutional background, were weighed against the gravity of the offence and the absence of any meaningful causal connection between illness and conduct.

A guilty plea entered at an early stage attracted a reduction of approximately 25 percent from the starting point of 30 years. The court declined to find special circumstances warranting a reduced non-parole period proportion, noting that the lengthy sentence would generate a parole eligibility period adequate for rehabilitation, and that a lesser non-parole period would not adequately reflect the offender's criminality.

Orders Made

  • Non-parole period of 17 years and 6 months, commencing 6 February 2017 and expiring 5 August 2034
  • Balance of term of 5 years and 6 months, commencing 6 August 2034 and expiring 5 February 2040
  • Eligible for release on parole on 6 August 2034

Key Takeaways

  • A background diagnosis of schizophrenia does not automatically establish a causal link between mental illness and a murder where, at the time of the offence, the offender was not experiencing active psychotic symptoms and acted with deliberate planning and rational purpose.
  • The substantial impairment partial defence under section 23A of the Crimes Act 1900 was not made out where the offender's conduct was premeditated, goal-directed, and motivated by a preference for prison over hospital rather than any delusional belief or psychotic episode.
  • Committing a serious offence with the deliberate objective of attracting a long prison sentence does not preclude a discount for the utilitarian value of a guilty plea; the personal motive behind the plea does not displace the entitlement to a sentencing reduction.
  • Special circumstances warranting a departure from the statutory non-parole period proportion were not established where the sentence was already lengthy enough to produce an adequate parole eligibility period and where a reduced non-parole period would understate the offender's criminality.
  • Continuing danger to the community, particularly in institutional settings, operated as a significant aggravating factor under section 21A(2) of the Crimes (Sentencing Procedure) Act 1999.

Legislation and Cases Referenced

Legislation
- Crimes Act 1900 (NSW), s 23A (substantial impairment by abnormality of mind)
- Crimes (Sentencing Procedure) Act 1999 (NSW), ss 21A(2), 61
- Mental Health (Forensic Provisions) Act 1990 (NSW), s 43A

Cases
- Cramp v R [2016] NSWCCA 305
- Kelsall v R [2017] NSWCCA 240
- Laurie v R [2015] NSWCCA 77
- Potts v R [2012] NSWCCA 229
- R v Heatley [2006] NSWSC 1199
- R v Hejabian [2016] NSWSC 1692
- R v Impson [2018] NSWSC 1490
- R v Morris [2017] NSWSC 637
- R v Neave [2012] NSWSC 229
- R v Poynton [2018] NSWSC 1693