This article was written by Fernanda Dahlstrom - Content Editor - Brisbane


Is Intoxication a Defence?

An accused person’s intoxication may be relevant when assessing their criminal responsibility. However, it is not a defence. When considering a person’s intoxication it is important to understand the distinction between voluntary and involuntary intoxication. Intoxication may be relevant when assessing whether a person had a particular intention and how they perceived a set of facts.

What is intoxication?

In the 1945 New Zealand decision of R v Ormsby, Justice Fair directed the jury that a man is intoxicated if ‘as a result of his consumption of intoxicating liquor, his physical and mental faculties, or his judgment, are appreciably and materially impaired in the conduct of the ordinary affairs of his daily life.’ Intoxication can also be the result of taking illicit drugs or even prescription medication.

Intoxication can be voluntary (ie the accused freely chose to drink alcohol or take drugs).

Intoxication can also be involuntary (ie the accused was forced or tricked into drinking alcohol or taking drugs). This can occur when a person is threatened if they don’t consume alcohol or drugs, when they are dosed with a drug without their knowledge or when they are unexpectedly affected by side-effects of medication.


Section 428C of the New South Wales Crimes Act 1900 provides:

  • However, such evidence cannot be taken into account if the person:

When is intoxication relevant?

The intoxication of an accused can be relevant when dealing with offences of specific intent. These are offences that can only be proven if the court is satisfied that the accused intended to cause a particular result. Example of specific intent offences are:

  • Stealing, where the accused must have intended to permanently deprive someone of their property;
  • Intentionally causing serious injury, where the accused must have committed an assault that involved deliberately inflicting serious injury;
  • Burglary, where the accused must have entered a building as a trespasser with the intent to commit a crime inside the building;
  • Murder, where the accused must have intended to kill the victim.

When a person is tried for an offence of specific intent, they can be acquitted if the court is satisfied that they were so intoxicated that they could not have formed the requisite intent. When the defence has raised intoxication of the accused, the prosecution must prove beyond a reasonable doubt that the accused had the requisite intent despite their intoxication.

Intoxication and the ‘reasonable person’ test

Where the defence relies on the accused’s intoxication to argue that they did not have the requisite intention to be found guilty of an offence, the court must compare the accused’s state of mind with the state of mind of a reasonable person. When the court does this, it must consider the state of mind of a reasonable sober person and not a reasonable drunk person.

Expert evidence

Where the defence relies on evidence of the accused’s intoxication, expert evidence may need to be called. This is particularly the case where the intoxication was caused by a substance other than alcohol, which members of the jury may not have experience with. Expert witnesses may be called to give evidence of the effects of a substance – for example, whether the substance could impair a person’s ability to reason and form an intention.





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