Self-defence/defence of another (General defences - Core principles of criminal liability)

Question 1

In what types of offences is self-defense available as a defence under criminal law?

Answer 1

It is available for crimes involving the use of force, such as assault, murder, manslaughter, and similar offences.

Question 2

What are the five lawful purposes for which reasonable force may be used?

Answer 2

Self-defense, defense of another, defense of property, prevention of crime, and lawful arrest.

Question 3

What two key questions must a jury ask when evaluating a self-defense claim?

Answer 3

(1) Was any force necessary in the circumstances?

(2) Was the force used reasonable in the circumstances?

Question 4

How are the circumstances assessed when determining whether force was necessary and reasonable?

Answer 4

Subjectively—based on what the defendant honestly believed the circumstances to be at the time.

Question 5

Can a defendant rely on self-defense if their belief about the circumstances was mistaken?

Answer 5

Yes, if the belief was honestly held, even if it was mistaken, the defence may still apply.

Question 6

Does the force used have to be exactly proportionate to the threat faced?

Answer 6

The force must be reasonable—not excessive—in relation to what the defendant honestly believed the threat to be.

Question 7

Can self-defense still apply if the defendant’s belief about needing force is later proven false?

Answer 7

Yes, as long as the belief was honest, even if unreasonable or mistaken, the defence may succeed.

Question 8

What role does the defendant’s credibility play in a self-defense claim?

Answer 8

The jury must assess whether the defendant’s account of belief in the threat and force used is credible and honestly held.