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Supreme Court 14 December 2007

REGINA v MAWSON

[2007] NSWSC 1473

Homicide
MANSLAUGHTER DIMINISHED RESPONSIBILITY SENTENCE

Citation: Regina v Mawson [2007] NSWSC 1473
Court: Supreme Court of New South Wales (Common Law Division)
Date: 14 December 2007
Judge(s): Adams J

Background

The offender, a man aged nearly 61 at the time of the offence, was indicted for the murder of a 32-year-old man at Padstow on 11 January 2006. He pleaded not guilty to murder but guilty to manslaughter, and the Crown accepted that plea in full satisfaction of the indictment. The basis for the reduced charge was the operation of s 23A of the Crimes Act 1900, which reduces liability from murder to manslaughter where an abnormality of mind substantially impairs the offender's mental responsibility.

The offender had served as a conscript soldier in Vietnam in 1967 and 1968, where he endured severe combat trauma. On his return to Australia, he developed chronic post-traumatic stress disorder (PTSD) and, over subsequent decades, alcohol dependence that psychiatrists considered had caused acquired brain injury. A visit to Vietnam in late 2005, intended by an acquaintance to be therapeutic, significantly worsened his symptoms in the months before the offence.

Multiple psychiatrists and a psychologist provided reports confirming that, at the time of the killing, the offender's PTSD and acquired brain injury produced an abnormality of mind that impaired his capacity to reason, his judgment of right and wrong, and his ability to control his actions. Adams J accepted that, had either the offender or the deceased been mentally well, the tragedy would not have occurred.

  • Whether the plea of guilty to manslaughter on the basis of diminished responsibility under s 23A of the Crimes Act 1900 was properly accepted.
  • What sentence was appropriate, having regard to the offender's mental condition, military service, remorse, and guilty plea.
  • Whether special circumstances existed to justify departing from the standard non-parole period ratio under s 44 of the Crimes (Sentencing Procedure) Act 1999.
  • What discount should be applied for a guilty plea entered at the first practicable occasion.

Decision

Adams J was satisfied that the medical evidence squarely supported the manslaughter plea under s 23A. The offender's PTSD and acquired brain injury substantially impaired his mental responsibility at the time of the killing, reducing his culpability from murder. The court found it entirely proper that the Crown accepted the plea on that basis.

On sentence, the court held that the offender's mental condition significantly reduced his criminal culpability. Because his abnormality of mind was so closely connected to the offending, the court considered it inappropriate to give significant weight to general deterrence. Personal deterrence was also discounted, with the court satisfied that the offender's rehabilitation prospects were good and re-offending of this kind was most unlikely.

The court also treated the offender's military service as a moderating factor in its own right. His PTSD was traced directly to his Vietnam service, including combat trauma of an extreme nature. Adams J described him as having "returned from Vietnam as one of the walking wounded," with an invisible but deep and permanent injury. The court accepted that the offender was genuinely remorseful.

A 25 per cent discount was applied for the guilty plea, entered at the first practicable occasion, in accordance with the Court of Criminal Appeal's approach in R v Thomson; R v Houlton. Special circumstances were found to exist, justifying a longer than usual balance of term, because the offender's mental condition made imprisonment harder to endure, this was effectively his first custodial sentence, and he would require extended supervision on parole.

Orders Made

  • The offender is sentenced to a total term of seven years' imprisonment commencing 11 January 2006.
  • Non-parole period: four years.
  • Balance of term: three years.
  • The offender is eligible for release on parole on 10 January 2010.

Key Takeaways

  • Under s 23A of the Crimes Act 1900, an abnormality of mind that substantially impairs an offender's capacity to reason, judge right from wrong, and control their actions can reduce criminal liability from murder to manslaughter on the ground of diminished responsibility.
  • Where an offender's mental impairment is directly causally connected to the offending conduct, a sentencing court may significantly reduce the weight given to both general and personal deterrence.
  • Military service resulting in severe and lasting psychiatric injury can independently moderate an offender's sentence, beyond its role in establishing diminished responsibility.
  • A guilty plea entered at the first practicable occasion attracted a 25 per cent discount, consistent with the Court of Criminal Appeal's approach in R v Thomson; R v Houlton [2000] NSWCCA 309.
  • Special circumstances justifying departure from the standard non-parole ratio were established where a mental condition made imprisonment more burdensome and extended post-release supervision was considered necessary for rehabilitation.

Legislation and Cases Referenced

Legislation:
- Crimes Act 1900 (NSW) s 23A (diminished responsibility)
- Crimes (Sentencing Procedure) Act 1999 (NSW) s 44 (standard non-parole period ratio)

Cases:
- R v Thomson; R v Houlton [2000] NSWCCA 309; (2000) 49 NSWLR 383 (guilty plea discount)