The Defence of Insanity

1 – Insanity/ Unsoundness of mind – Section 27 of the Criminal Code

• This defence will only apply if the evidence suggests the alleged offender responsible for was, at the time of the act, in such a state of mental disease or natural mental infirmity as to deprive them of the capacity to:

• • understand what they are doing, or 
  • control their actions, or 
  • know that they should not do the act.
• If the evidence suggests a person was deprived of any of the relevant 3 capacities above, the law in Queensland says that they should not be criminally responsible for their actions in perpetrating the offence. 
• If a person is suffering from delusions but not deprived of one of the above three relevant capacities, they will be criminally responsible for the act to the same extent as if the real state of things had been such as the person was induced by the delusions to believe to exist.
• When raising the defence of insanity, an accused person contends with the assumption at law that every person is presumed to be of sound mind–until the contrary is proved. Because of this, to raise the defence of insanity successfully, the accused will usually need to rely upon expert psychiatric evidence which indicates they were deprived of one or more of the three relevant capacities.  
• For indictable matters, the question of insanity will often be determined through a reference of the matter to the Mental Health Court, but in some cases, the question may be left to a jury. 
• For summary and simple offences (those which are usually finalised in the Magistrates Court) applications can be made before a Magistrates Court for the dismissal or charges on the basis that a person was of unsound mind at the time of the offending. The evidence required for this application will usually need to come from a qualified mental health clinician. 
• If the Mental Health Court decides the person was of unsound mind at the time of the offence, the offence will generally be dismissed and the person ordered to be subject of a Forensic Order or a Treatment Support Order. These orders are generally made up of conditions designed to address the person’s mental health treatment and protect the community from future harm by mentally unwell person and are generally reviewed regularly by the Mental Health Review Tribunal. 
• A person will generally be excluded from reliance on the defence of insanity where they have, to any extent, intentionally caused themselves to become intoxicated by alcohol or drugs.

2 – Where the Defendant is ‘Unfit’ for trial

• In some cases, where the defence of insanity is potentially open on the evidence, the question of “fitness for trial” may also be in issue, but the test for fitness for trial differs from the test for unsoundness of mind.
• In some cases, a person’s mental illness or intellectual disability may make them unable to instruct their lawyer properly and endure a trial.
• While “fitness to plead” is no longer defined in the Mental Health Act 2016 (Qld), the common law in Queensland, through the case of R v Presser [1958] VR 45, provides that a person will generally be “unfit for trial” if, by virtue of their illness or disability, they are unable to:
  • Make an informed decision about whether to plead guilty or plead not guilty
  • Understand the nature of Court proceedings
  • Be able to follow the course of proceedings and understand in a general sense, the effect of evidence given
  • Be able to meaningfully respond to evidence, instruct their lawyer or provide their own version themselves 
  • Decide what defence, if any, they will rely upon and to make that defence
• If, upon hearing expert evidence from qualified psychiatrists, the Mental Health Court decides the person is unfit for trial, the Court must also decide whether the unfitness for trial is permanent or whether the person may become fit to instruct in the future. In some cases, proceedings can be stayed or delayed to allow for this to occur, and the person’s fitness for trial will generally be periodically reviewed by the Mental Health Review Tribunal, with the Court proceedings resuming again if/when the person becomes “fit” again.
• If the Mental Health Court decides the person is unfit for trial and the unfitness for trial is permanent: 
  • the proceeding against the person for the offence is usually discontinued; and
  • the person is usually placed on a Forensic Order or a Treatment Support Order; and
  • further proceedings may not be taken against the person for the offence.