What is Self Defence in Criminal Law?

What is self defence in Criminal Law?

Self defence in criminal law is a complete legal defence that, if established, renders a person ‘not criminally responsible’ for otherwise unlawful conduct such as assault, cause injury and affray charges. In order to rely on self-defence in court, there must be some evidence supporting the defence being raised.

However, once the defence is raised, it is up to the prosecution to prove, ‘beyond reasonable doubt’, that the person did not carry out their conduct in self-defence. A decision by the accused not to raise self-defence does not automatically prevent the court from considering it. The defence may still be left for consideration by a jury in the appropriate circumstances.

When does self defence apply?

Self-defence applies in situations where a person carries out conduct to:

  • defend themselves or another person;
  • protect against the unlawful deprivation of their liberty or the liberty of another person;
  • to protect property from being taken, destroyed, damaged or interfered with; or
  • prevent criminal trespass to any land or premises or to remove a person committing trespass.

Importantly, the infliction of death, whether intentionally or recklessly, only to protect property or prevent trespass does not constitute self-defence. See section 420 Crimes Act 1900 NSW.

How far can self defence go?

For the defence to apply, the conduct of the person must be necessary and proportionate to the circumstances as perceived by them. This requires the court to ask two questions:

  1. was there a reasonable possibility that the person believed their conduct was necessary to defend themselves; and
  2. was there also a reasonable possibility that what the person did was a reasonable response to the circumstances as they perceived them.

The first question requires an assessment as to whether the person subjectively, in their own mind, believed their conduct was necessary. The accuracy of the belief is not important so long as the very fact of the belief can be adduced.

In determining whether such a belief existed, it is not necessary for the accused person to give evidence about their belief unless they want to. Inferences about the accused’s belief can be drawn from other sources of evidence. Furthermore, the personal characteristics and mental health history of the accused should be considered when determining whether the accused believed their actions were necessary.

The second question requires an objective determination of what is reasonable in the context of the person’s subjective perception of events. In other words, was the conduct proportionate to what a reasonable person would do in the circumstances perceived by the accused? Unless the prosecution can prove ‘beyond reasonable doubt’ that the accused did not believe their conduct was necessary, or that the conduct was not reasonable, self-defence will apply and absolve the accused. The use of excessive force in self-defence that inflicts death, where it was not a reasonable response to the circumstances, will only serve to reduce a murder charge to manslaughter.

The timing of the accused’s actions is also important. Self defence cannot be used to justify retaliation or revenge after an incident has occured, where there is no perceived imminent threat of harm. In the context of domestic violence, this requirement of immediate harm has been criticised as it fails to acknowledge how long-term abuse by intimate partners can lead to a continual apprehension of harm.

Does self defence apply while intoxicated?

The short answer is yes, self defence may still be valid even when a person is voluntarily intoxicated. Intoxication is an important factor to consider when determining whether the accused believed their conduct was necessary, as being intoxicated obviously influences a person’s perception of events. However, intoxication cannot be taken into account when determining whether the actions taken by the accused were reasonable and proportionate to the perceived threat.

Contact one of Sydney’s best Criminal Law firms

If you would like advice on how to avoid a conviction for an assault offence, our professional team of Sydney-based criminal lawyers are here to help. Call 1800 100 529 for 24/7 legal assistance or submit your enquiry online using our form.