Defences in Criminal Law: Key Case Summaries

R v Martin (2002)

Self-defence: Excessive force invalidates the defence.

R v Clegg (1995)

Self-defence: Excessive force invalidates the defence, even for soldiers.

R v Gladstone Williams (1987)

Self-defence: Mistaken belief can justify defence.

R v O'Grady (1987)

Self-defence: Intoxicated mistake invalidates defence.

R v Bird (1985)

Self-defence: No duty to retreat.

R v Beckford (1988)

Self-defence: Pre-emptive strikes are allowed.

R v Hussain (2010)

Self-defence: Excessive force invalidates defence.

R v Collins (2016)

Self-defence: Householder cases allow greater force.

R v Ray (2017)

Self-defence: Reasonable force in householder cases.

R v Keane (2010)

Self-defence: Provoking the attack invalidates defence.

R v Bailey (1983)

Automatism: Self-induced automatism invalidates defence.

R v Hardie (1984)

Automatism: Unexpected reaction to drugs may allow defence.

R v Kingston (1994)

Intoxication: Involuntary intoxication is no defence if intent is still formed.

R v Majewski (1977)

Intoxication: Voluntary intoxication is no defence for basic intent crimes.

R v Allen (1988)

Intoxication: Mistake over strength of drink does not provide defence.

R v Lipman (1970)

Intoxication: Voluntary intoxication prevents murder conviction.

R v Sheehan and Moore (1975)

Intoxication: Voluntary intoxication prevents intent formation.

R v Coley (2013)

Intoxication: Voluntary intoxication provides no defence.

R v T (1990)

Automatism: PTSD as an external factor can provide defence.

Bratty v AG for NI (1963)

Automatism: Defence for involuntary actions.

R v Quick (1973)

Automatism: External cause (insulin) justifies defence.

R v Hennessy (1989)

Automatism: Internal cause (diabetes) qualifies as insanity.

R v Clarke (1972)

Insanity: Absent-mindedness is not insanity.

M'Naghten (1843)

Insanity: Legal test for insanity.

R v Windle (1952)

Insanity: Knowing the act is wrong invalidates the defence.

R v Sullivan (1984)

Insanity: Epilepsy qualifies as a disease of the mind.

R v Burgess (1991)

Insanity: Sleepwalking can be insanity.

R v Kemp (1957)

Insanity: Arteriosclerosis as disease of the mind.

R v Johnson (2007)

Insanity: Paranoid schizophrenia provides insanity defence.

R v Codere (1916)

Insanity: Inability to understand the nature of the act.