Self-defence is a complete defence to crimes of violence — when force is justified, how much is permitted, and where the law draws the line.
A successful plea of self-defence results in outright acquittal, which is why the courts police its boundaries so carefully. This chapter starts with the defence's common law and statutory sources, including section 3 of the Criminal Law Act 1967 and where the burden of proof lies, before setting out the two-stage test and the subjective and objective elements within it. It then examines the defendant's belief in the need for force — covering mistaken beliefs and the effect of voluntary and involuntary intoxication — and how the reasonableness of force is judged, from pre-emptive strikes and the absence of a duty to retreat to instinctive reactions and the defence of property. It closes with the more generous householder standard and the limits of the defence, including initial aggressors, force used after the threat has passed, and resistance to unlawful arrest.
