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Mental Impairment

The Criminal Law Consolidation (Mental Impairment) Amendment Act 2017 (SA) has changed this area of the law substantially to:

  • limit cases where mental incompetence has been caused by self-induced intoxication
  • ensure the paramount consideration when determining whether to release a defendant on licence, is the safety of the community
  • enable matters to be dealt with through fewer reports,
  • provide more options for dealing with less serious, summary and minor indictable, matters.

Section 269C of the Criminal Law Consolidation Act 1935 (SA) outlines a general defence of Mental Impairment, where because of a mental illness, intellectual disability or a disability or impairment of the mind resulting from senility, the defendant did not know the nature and quality of their conduct or could not reason that what they did was wrong or were totally unable to control their conduct.

The law recognises that such persons do not have the mental element of a guilty mind that is required to be found guilty of a criminal offence.

Sub-section 269C(2) now sets out that where a person is found to be mentally incompetent to have committed the offence, but the trial judge is satisfied, on the balance of probabilities, that the mental impairment was substantially caused by self-induced intoxication, the person may be dealt with instead under Part 8, see Intoxication. Sub-sections 269A(2a) and (2b) states that intoxication resulting from recreational use of drugs or the combined effect of therapeutic and recreational use, the intoxication is to be regarded as self-induced.

There is a presumption of mental competence [s 269D] and to make use of the mental impairment defence, mental incompetence must be shown on the balance of probabilities. The possible consequences of a finding of mental impairment are unconditional release or release on strict conditions of supervised licence or detention in secure psychiatric care [ss 269NB and 269O]. It is a condition of every licence for release that the defendant be prohibited from possessing firearms and ammunition. The Court may also direct a defendant to surrender a firearm [ss 269NC and 269OA]. When determining whether to release a defendant, either unconditionally or on a licence, the paramount consideration must be the safety of the community [ss 269NA and 269NI].

Mental Impairment  :  Last Revised: Fri Dec 1st 2017
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