General defences - Duress and necessity

Learning Outcomes

This article examines the general defences of duress (by threats and of circumstances) and necessity in criminal law. After reading this article, you should understand the core elements required for each defence, the key distinctions between them, the limitations on their availability (particularly concerning serious offences like murder), and how these principles apply to factual scenarios relevant to the SQE1 assessment. This knowledge will assist you in analysing criminal liability problems and identifying potential defences.

SQE1 Syllabus

For SQE1, you are required to understand the core principles of criminal liability, including the operation of general defences. Duress and necessity are key general defences that negate liability where specific conditions are met. Your understanding of these defences is essential for advising clients and assessing criminal culpability in practice-based scenarios.

During your revision, ensure you are familiar with:

• The elements required to establish duress by threats, including the nature of the threat, its target, and the objective/subjective test for the defendant's response (R v Graham, R v Hasan).
• The elements required for duress of circumstances, focusing on the imminent danger and proportionality of the response (R v Martin (Colin)).
• The defence of necessity, its limited application, particularly in medical contexts (Re A (Children)), and its distinction from duress.
• The limitations on the availability of duress, especially its exclusion for murder and attempted murder (R v Howe, R v Gotts), and where the defendant has voluntarily associated with criminals (R v Sharp).
• The distinction between duress and necessity, focusing on the source of the compulsion and the offences to which they apply.

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. Which defence involves committing an offence due to threats of death or serious injury from another person?
   1. Necessity
   2. Self-defence
   3. Duress by threats
   4. Duress of circumstances
2. Which infamous case established that duress is not a defence to murder?
   1. R v Graham
   2. R v Hasan
   3. R v Howe
   4. Re A (Children)

3. True or False: The defence of necessity requires the defendant to subjectively believe they faced imminent danger, regardless of whether that belief was reasonable.

4. What is the key difference between duress of circumstances and necessity?

Introduction

When a defendant (D) has committed the actus reus of an offence with the required mens rea, they may still avoid criminal liability if they can successfully raise a defence. Duress and necessity are general defences, meaning they can potentially apply to a wide range of offences, unlike specific defences (e.g., loss of control for murder). Both defences operate on the principle that D was compelled to act unlawfully due to extreme circumstances, effectively negating the voluntariness of their actions (duress) or justifying their actions as the lesser of two evils (necessity). For the SQE1 assessment, you must be able to distinguish between these defences and apply their specific legal tests to factual scenarios.

Duress

Duress operates as an excusatory defence, meaning it excuses D's conduct because it was not truly voluntary. It arises where D commits an offence because they are threatened with death or serious injury, or reasonably believe they face such a threat from the surrounding circumstances.

Key Term: Duress
A general defence where the defendant is compelled to commit an offence due to threats of death or serious injury, or perceived imminent danger of death or serious injury arising from the circumstances.

The defence is traditionally divided into two types: duress by threats and duress of circumstances.

Duress by Threats

This applies where D commits an offence because another person (X) threatens D (or someone D is responsible for) with death or serious personal injury if D does not comply.

The leading authority is R v Hasan [2005] UKHL 22, which confirmed a strict two-part test derived from R v Graham [1982] 1 WLR 294:

1. Subjective Test: Did D reasonably believe they faced a threat of death or serious injury, and was D compelled to act as they did because of that belief?
2. Objective Test: Would a sober person of reasonable firmness, sharing D's relevant characteristics, have responded to the threat in the same way?

Key Term: Duress by threats
A defence available when D commits an offence due to threats of death or serious personal injury made by another person.

Several conditions must be met for the defence to succeed:

• Nature of the Threat: The threat must be of death or serious personal injury (GBH). Threats of lesser harm (e.g., damage to property, minor injury, revealing secrets) are insufficient.
• Target of the Threat: The threat can be directed at D, their immediate family, or someone for whose safety D would reasonably regard themselves as responsible.
• Imminence and Evasion: The threat must be imminent or immediate, operating on D's mind at the time the offence was committed. There must have been no reasonable opportunity for D to evade the threat or seek police protection (R v Hudson & Taylor [1971] 2 QB 202, though Hasan suggests a stricter approach to evasive action).
• Causation: The threat must be the direct cause of D committing the offence. D must have acted because of the threat.
• Voluntary Association: The defence is unavailable if D voluntarily associated with individuals engaged in criminal activity, knowing they might be subjected to compulsion by threats of violence (R v Sharp [1987] QB 853; R v Hasan). The test is whether D foresaw or ought reasonably to have foreseen the risk of being subjected to any compulsion by threats of violence.

Worked Example 1.1

Anya is forced by a violent gang leader, known for extreme brutality, to drive the getaway car for a robbery. The leader threatens to kill Anya's child if she refuses. Anya complies, terrified for her child's safety. She had no opportunity to contact the police between the threat and the robbery. Can Anya raise duress by threats?

Answer: Yes, Anya may potentially raise duress by threats. The threat is of death to her child (someone for whom she is responsible). Assuming the threat was imminent and she had no reasonable opportunity to seek police protection or escape, the defence could apply if a sober person of reasonable firmness sharing Anya's relevant characteristics (e.g., as a mother fearing for her child) might have responded similarly. The prosecution would need to disprove one element beyond reasonable doubt. Her prior association with the gang (if any) and foreseeability of compulsion would be key factors (Hasan).

Duress of Circumstances

This defence arises where D is forced to commit an offence due to surrounding circumstances, rather than threats from a specific person. The perceived threat must still be of death or serious injury. The test is essentially the same as for duress by threats, adapted for the circumstances.

Key Term: Duress of circumstances
A defence available when D commits an offence due to external circumstances creating an imminent threat of death or serious personal injury.

The key case is R v Martin (Colin) [1989] 1 All ER 652, where D drove whilst disqualified because his wife threatened suicide if he did not drive their son to work. The court held the principles of duress could apply to pressure from circumstances.

• D must reasonably believe the circumstances pose a threat of death or serious injury.
• D's actions must be a reasonable and proportionate response to that perceived threat.
• There must be no realistic alternative course of action.

Exam Warning

Duress of circumstances often overlaps with the defence of necessity. However, they remain distinct. Duress (of both types) focuses on the compulsion acting on D's will, making the act involuntary in a moral sense. It is generally viewed as an excuse. Necessity, explored next, focuses on justifying the act as the lesser of two evils (necessity).

Limitations on Duress

Duress (both by threats and circumstances) is not available for:

• Murder: Established in R v Howe [1987] AC 417. The sanctity of human life outweighs the duress faced by D. This applies even to secondary parties.
• Attempted Murder: Confirmed in R v Gotts [1992] 2 AC 412. The logic is that if duress is not available for the completed offence, it should not be available for the attempt.
• Treason: Some historical authority suggests duress is not available for treason, though this is less certain.

Necessity

Necessity is a defence of justification, arguing that D's actions, although technically unlawful, were necessary to prevent a greater evil. It operates in extremely limited circumstances and is distinct from duress.

Key Term: Necessity
A defence justifying an otherwise unlawful act performed to avoid a greater harm, where the harm inflicted is not disproportionate to the harm avoided.

The courts have been reluctant to formally recognise a general defence of necessity, fearing it could become a charter for lawlessness (Southwark LBC v Williams [1971] Ch 734). However, it has been successfully invoked, most notably in medical cases.

The key elements, often drawn from the obiter dicta in Re A (Children) (Conjoined Twins: Surgical Separation) [2001] Fam 147, are:

1. The act was done only to prevent an act of inevitable and irreparable evil.
2. No more was done than was reasonably necessary for the purpose to be achieved.
3. The evil inflicted was not disproportionate to the evil avoided.

Worked Example 1.2

A firefighter breaks down the door of a burning house to rescue a trapped child, causing criminal damage. Can the firefighter rely on necessity?

Answer: Yes. The act (breaking the door) was necessary to prevent inevitable and irreparable evil (the child's death or serious injury). No more was done than reasonably necessary (breaking the door was required for rescue). The evil inflicted (criminal damage) was not disproportionate to the evil avoided (saving a life).

Limitations on Necessity

• Murder: Generally, necessity is not a defence to murder (R v Dudley and Stephens (1884) 14 QBD 273 – shipwrecked sailors killing cabin boy). However, Re A created a very narrow exception for the unique medical situation of separating conjoined twins where one would inevitably die, justifying the killing of one to save the other. This case is highly fact-specific and does not establish a general necessity defence to murder.
• Narrow Application: The defence is applied very restrictively by the courts. It cannot be used simply because D believes their actions are morally justified or to challenge the law itself.

Revision Tip

Focus on the core test from Re A when considering necessity. Remember its extremely limited scope, especially regarding homicide. Contrast it clearly with duress of circumstances: necessity justifies the act as the 'lesser evil', while duress excuses the act due to compulsion.

Worked Example 1.3

David is driving dangerously over the speed limit. He claims he did so out of necessity because his passenger suddenly suffered a severe asthma attack, and he was rushing them to the hospital only a mile away, fearing they might die otherwise. The passenger recovered fully. Could necessity apply?

Answer: Potentially, but it is difficult. David would need to show the danger (death from asthma attack) was imminent and inevitable without speeding, that speeding was reasonably necessary (e.g., no time to call an ambulance?), and that the 'evil' of dangerous driving was not disproportionate to the evil of the passenger dying. It might be argued that dangerous driving itself creates a significant risk to others, making the proportionality difficult to establish. Duress of circumstances might be a more suitable, though still challenging, defence here, focusing on the compulsion created by the emergency.

Key Point Checklist

This article has covered the following key knowledge points:

• Duress and necessity are distinct general defences in criminal law.
• Duress (by threats or circumstances) requires a threat of death or serious injury compelling D to act, subject to the Graham/Hasan test (subjective belief + objective reasonableness).
• Duress is not a defence to murder or attempted murder.
• Voluntary association with criminals may preclude the defence of duress.
• Necessity is a defence of justification applicable in very limited circumstances, requiring the act to be a proportionate response to prevent inevitable and irreparable evil (Re A).
• Necessity is generally not a defence to murder, except in highly specific medical situations like Re A.

Key Terms and Concepts

• Duress
• Duress by threats
• Duress of circumstances
• Necessity