The prosecutor must disprove self defence beyond reasonable doubt. If the prosecutor fails to disprove at least one of the two elements of self defence the accused will be entitled to an acquittal.

Self defence is governed in Victoria by the common law. In homicide situations, statutory self defence provisions exist in the Crimes Act 1958. Section 9AC is the provision to be used in murder cases and section 9AE is to be used in manslaughter cases.

Elements of Self-Defence

The High Court has defined the test for self defence, for both homicide and non-homicide cases.
The question to be asked in the end is quite simple. It is whether the accused believed upon reasonable grounds that it was necessary in self-defence to do what he or she did. – Zecevic v DPP (1987) 162 CLR 645 at 661 per Wilson, Dawson and Toohey JJ.

There are two elements to this test:

1. The accused must have believed at the time that s/he committed the relevant act that what s/he was doing was necessary – the subjective element.

This is a subjective test. It does not involve a consideration of what a reasonable person would have believed in the circumstances, but rather what the accused believed. For this element to be satisfied, it does not matter if the accused’s belief was mistaken but it must have been genuinely held.

If the accused was intoxicated at the time s/he committed the relevant offence, this can be taken into account when determining whether s/he believed their actions to be necessary.

2. That belief must have been based on reasonable grounds – the objective element.

This element does not require the jury to determine whether the accused acted reasonably under the circumstances. Rather, it requires the jury to determine whether there were reasonable grounds for the accused’s belief that it was necessary to do what he or she did.

In determining whether the accused’s belief was based on reasonable grounds, the jury may take into account the following issues:

  • circumstances around the offence
  • the accused’s knowledge (including facts they knew)
  • any relationship between the accused and the deceased/complainant
  • prior behaviour of the deceased/complainant
  • the personal characteristics of the accused, such as any deluded beliefs s/he held and any excitement, affront or distress s/he was experiencing
  • proportionality of actions by the accused
  • whether the accused failed to retreat when they had a chance

Where the Accused Initiated the Aggression

Persons who originate an attack cannot then claim that they acted to defend themselves against a counter attack, unless their original aggression stopped at the time of the counter attack.

Self-Defence Against Lawful Force

You can run a self defence argument even if you are responding to the lawful use of force. For fairly obvious reason this will be restricted to exceptional situations in which a lawful attack would provide reasonable grounds for acting in self-defence.