General Defences

General defences in criminal law allow a defendant to avoid liability even if the prosecution proves the elements of an offence. The main general defences include self-defence, duress (by threats and by circumstances), necessity, and consent. These defences are vital for understanding how English law balances justice and fairness.

Self-Defence

Self-defence is a legal justification for using force to protect oneself, others, or property from unlawful harm. It applies both to common law offences and those under statutory provisions.

Definition: The use of reasonable force to defend oneself, another person, or property against an imminent threat.

Key Elements:

• The force used must be reasonable and necessary in the circumstances as the defendant believed them to be.
• Section 76 of the Criminal Justice and Immigration Act 2008 outlines the statutory framework for self-defence.
• Excessive force will negate the defence; the response must be proportionate to the perceived threat.

Application: The defence is available for both private and public defence, including defence of others and prevention of crime.

Case Law: Key cases include R v Gladstone Williams (1984) and R v Martin (Anthony) (2001).

Duress by Threats

Duress by threats is a defence where the defendant claims they committed a crime because they were forced to do so by threats of death or serious injury.

Definition: Duress by threats occurs when a person commits a crime as a direct result of being threatened with death or serious harm.

Rules:

• The threat must be of death or serious injury and be immediate or imminent.
• The threat must be directed at the defendant or someone close to them (e.g., family).
• The defendant's response must be reasonable given the circumstances.
• Duress is not available for murder, attempted murder, or some forms of treason.

Case Law: R v Graham (1982) established the two-stage test, and R v Howe (1987) held that duress is not available for murder.

Duress of Circumstances

This defence applies when a defendant is forced to act unlawfully due to the circumstances, rather than threats from another person.

Definition: Duress of circumstances arises when a person commits a crime because the circumstances leave them no reasonable alternative but to break the law to avoid greater harm.

Rules:

• The threat must be of death or serious injury, arising from the circumstances rather than a specific threat.
• The conduct must be a reasonable and proportionate response to the danger faced.
• As with duress by threats, not available for murder or attempted murder.

Case Law: R v Conway (1988) and R v Martin (Colin) (1989) developed the defence.

Necessity

Necessity is a rarely accepted defence, closely related to duress of circumstances, where the defendant argues that their actions were required to prevent a greater evil.

Definition: Necessity exists when a defendant acts to prevent greater harm, and their actions are the only reasonable way to avoid that harm.

Rules:

• Generally not accepted as a defence except in limited circumstances (e.g., medical cases such as Re A (Children) (Conjoined Twins) (2000)).
• Must be the only way to prevent the greater harm.
• Not available for murder or attempted murder.

Consent

Consent is a defence where the victim voluntarily agrees to the defendant's conduct, negating criminal liability in specific circumstances.

Definition: Consent is the voluntary agreement by a person to another’s conduct, which may otherwise constitute a criminal offence.

Main Rules / Elements:

• Consent must be freely given, informed, and specific to the act.
• Consent is generally not a defence to serious harm, except in certain recognised activities (e.g., sports, surgery, tattooing).
• For sexual offences, consent must be genuine and not obtained by deception or coercion.
• Key cases include R v Brown (1993) and R v Wilson (1996).

Summary

Understanding the general defences of self-defence, duress (by threats and circumstances), necessity, and consent is essential for success in A-Level Law. These defences help balance the need for justice with the recognition of human frailty and fairness in the criminal justice system.