Self-Defence in the ACT

Self-defence in the ACT is a valid legal defence to violent offences, including murder and manslaughter. If the court determines that the accused acted in self-defence, the charge will be dismissed. The burden of proving that the accused did not act in self-defence lies with the prosecution and must be established beyond a reasonable doubt. This page deals with self-defence in the ACT.


In the ACT, self-defence is defined in Section 42 of the Criminal Code Act 2002. A person is not criminally responsible for an offence if they carry out the conduct required for the offence in self-defence. This includes protecting oneself or someone else, preventing or ending unlawful imprisonment, protecting property from unlawful appropriation, destruction, damage or interference, preventing criminal trespass to land or premises, or removing a person committing criminal trespass.

The accused’s conduct must be a reasonable response to the circumstances as perceived by the person.

What is not self-defence?

Using force that intentionally causes death or serious harm to protect property, prevent criminal trespass, or remove a person committing criminal trespass is not self-defence.

A person cannot claim self-defence when they have used force to respond to lawful conduct they knew was lawful (for example, a lawful arrest).

Burden of proof

The burden of proof when the issue of self-defence has been raised does not fall on the accused. In accordance with the ruling in Zecevic v DPP, once evidence has suggested the possibility that the accused acted in self-defence, it is the prosecution’s responsibility to prove beyond a reasonable doubt that the act was not committed in self-defence.

The jury must be instructed accordingly, even if the defence was not raised by the accused.

To refute self-defence, the prosecution must demonstrate either:

  • that the accused did not genuinely believe that their actions were necessary in self-defence; or
  • that their response was not reasonable in the circumstances and in light of the perceived danger.

How do courts assess whether it was self-defence?

When self-defence is raised, the court must answer two questions:

  • Is there a reasonable possibility that the accused believed their conduct was necessary for their own defence?
  • If so, is there also a reasonable possibility that the accused’s response was reasonable given the circumstances as they perceived them?

The first question is determined subjectively, considering the personal characteristics of the accused at the time of the conduct.

The second question is determined objectively, evaluating the proportionality of the accused’s response to the situation they believed they faced.

For the accused to successfully argue self-defence, the evidence must show that they genuinely believed that their actions were necessary in self-defence.

The jury, judge, or magistrate should consider factors such as age, gender, and health when evaluating the accused’s response, rather than assessing the response of a hypothetical “reasonable person.”

Self-defence and pre-emptive strikes

Self-defence can be invoked for a pre-emptive strike in response to an anticipated attack. In Australian courts, it is generally required that the accused’s belief that they were facing an imminent attack be reasonable, based on an objective view.

When defending another person from an imminent attack, an individual is entitled to use the same amount of force as they would be allowed to use if the attack was aimed at them. This applies regardless of the relationship between the defender and the other person, as established in the Victorian Supreme Court case of R v Portelli (2004) 10 VR 259, as stated by Ormiston, JA.

If you require legal advice or representation in any legal matter, please contact Go To Court Lawyers.


Michelle Makela

Michelle Makela is a Legal Practice Director at Go To Court Lawyers. She holds a Juris Doctor, a Bachelor of Science (Psychology) and a Master of Criminology. She was admitted to practice in 2006. Michelle has over 15 years experience in the legal industry, working across commercial litigation, criminal law, family law and estate planning. 
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