Defences 2: Necessity Defences (AQA A-Level Law): Revision Notes
Defences 2: Necessity Defences
Introduction to necessity defences
The AQA specification examines three key common law necessity defences that may be available to defendants in criminal cases. These defences acknowledge that sometimes individuals may be compelled to commit criminal acts due to external pressures or threats beyond their control. The three defences are:
- Self-defence and the prevention of crime - where force is used to protect oneself or others
- Duress by threats - where a defendant is forced to commit a crime through direct threats
- Duress of circumstances (commonly linked to necessity) - where circumstances create a situation requiring criminal action to avoid greater harm
These are complete defences, meaning a successful plea results in a full acquittal rather than a reduced sentence. This distinguishes them from partial defences (like diminished responsibility) which only reduce the severity of the conviction.
Each defence has evolved through common law, with judicial decisions establishing the boundaries and requirements that defendants must satisfy. Understanding the precise elements and limitations of each defence is essential for applying them correctly in legal scenarios.
Self-defence and the prevention of crime
Overview and coverage
Self-defence is using reasonable force in order to defend oneself. The most basic form of self-defence comes under common law and requires that it must be necessary to use force and reasonable to do so. This defence is available to crimes committed by force, and if successful, it provides a complete defence including to murder charges.
The fundamental principle was established in Palmer (1971), where the court stated:
It is both good law and good sense that a man who is attacked may defend himself. It is good law and good sense that he may do, but only do, what is reasonably necessary.
This principle captures the core balance between the right to defend oneself and the need to ensure force is not excessive.
The operation of self-defence was later clarified by s76 Criminal Justice and Immigration Act 2008, which specifically addressed the test of reasonableness. Because the defendant's use of force is considered justified in the circumstances, the defence completely exonerates their actions.
The defence is predominantly common law based and covers two main situations:
- Actions needed to defend oneself from attack
- Actions taken to defend another person
The two key elements of self-defence
Self-defence requires satisfaction of two distinct tests. Both elements must be present for the defence to succeed. Failure to satisfy either test will result in the defence failing completely.
1. The necessity test - was force needed at all?
This element asks whether it was necessary to use some force in the circumstances. The test is subjective, based on the defendant's genuine belief in those precise circumstances. Importantly, the defendant can be mistaken about the facts but can still successfully plead the defence if their belief was honestly held.
The law recognises that self-defence is not purely reactive. A pre-emptive strike is possible and allowable - the defendant can prepare for an attack and strike first if they genuinely believe an attack is imminent. Crucially, there is no duty to retreat before using force in self-defence.
2. The reasonableness test - was the force proportionate?
This element asks whether the degree of force used was reasonable in the circumstances. This is an objective test applied by the jury. The jury must consider: based on the facts as the defendant believed them to be, would a reasonable person regard the force used as reasonable or excessive?
Lord Morris provided important clarification in Palmer (1971) about what constitutes reasonable force. He acknowledged that a defendant acting 'in a moment of unexpected anguish' may not have been able to 'weigh to a nicety the exact measure of his defensive action'.
This recognises that split-second decisions made under threat should not be judged with the benefit of hindsight - the law allows for the reality of emergency situations.
However, even if an act was deemed necessary, the resulting action may still fail the reasonableness test. The reaction to the threat is always integral to the reasonableness of the force used, as demonstrated in Clegg (1995).
Critical Limitation: A mistake of fact while intoxicated will prevent the defence's application - O'Grady (1987). Defendants cannot rely on mistaken beliefs caused by voluntary intoxication.
Special provisions for householders
In 2018, the Crown Prosecution Service and the National Police Chiefs' Council issued a joint public statement titled 'Householders and the use of force against intruders'. This statement clarified that householders receive special consideration when defending their homes.
The guidance states that a householder must have acted honestly and instinctively and thought it necessary in the 'heat of the moment'. If these criteria are met, this provides the strongest evidence that they acted lawfully and in self-defence when reacting to an intruder or home invasion.
Section 76 Criminal Justice and Immigration Act 2008 specifically allows householders to use disproportionate force in self-defence. This is a lower threshold than applies to self-defence generally.
However, this is judged on a case-by-case basis, and the degree of force will still not be seen as reasonable if the householder's actions were grossly disproportionate.
Pre-emptive strikes, duty to retreat and revenge
The law recognises that sometimes the best defence is to act first. There is no legal requirement that a person must wait to be attacked before acting in self-defence. In the right circumstances, a person can strike first in an act of self-defence rather than wait to be attacked - Deana (1909).
Regarding the duty to retreat, failure to retreat and avoid conflict does not automatically prevent the application of the defence or prove that the defendant was not acting in self-defence. Evidence of whether the defendant attempted to retreat is relevant to the test of reasonableness, but it is not necessary for the defendant to walk away - Bird (1985).
Regarding revenge, the act of revenge does not automatically rule out the possibility of self-defence - Rashford (2005). However, if a person starts the violence themselves, they cannot then rely upon the defence to render their subsequent actions lawful.
Prevention of crime
Prevention of crime is governed by ss 2 and 3 Criminal Law Act 1967. The common law approach to self-defence is directly relevant to the defence of prevention of crime, which has a statutory definition under section 3 Criminal Law Act 1967:
A person may use such force as is reasonable in the circumstances in the prevention of crime.
The amount of force that may be used to stop or prevent a crime, and whether a defendant can use force in doing so, mirrors the test established for self-defence. The same necessity and reasonableness requirements apply.
Key cases for self-defence
R v Bird (1985)
- Facts: Bird gouged out the victim's eye during a major argument after the victim hit her first.
- Element: Duty to retreat
- Legal principle: Bird's conviction was quashed. The Court of Appeal held that evidence of an attempt to retreat is helpful to a defendant but is not essential to establish self-defence.
R v Williams (1987)
- Facts: Williams grabbed the victim, an off-duty police officer, whom he mistakenly thought was attacking a youth.
- Element: Mistaken use of self-defence/prevention of crime
- Legal principle: An honest but mistaken belief will allow the defence to operate. The conviction was quashed because Williams genuinely believed force was necessary.
A-G Ref. (No. 2 of 1983) (1984)
- Facts: The defendant kept petrol bombs for protection after his shop had been attacked several times during riots.
- Element: Pre-emptive strike
- Legal principle: A person is entitled to make preparations in self-defence for a future attack against them.
R v Clegg (1995)
- Facts: Clegg, a soldier, shot and killed a joyrider whom he thought was a terrorist.
- Element: Excessive force
- Legal principle: Clegg was not acting in self-defence because the last shot fired constituted excessive force since the perceived threat had passed.
R v Martin (Anthony) (2002)
- Facts: Martin, a farmer, shot and killed a burglar in his home.
- Element: Excessive force
- Legal principle: This was not self-defence because Martin shot the burglar when the burglar was making his escape, meaning the threat was no longer present.
R v Hussain (2010)
- Facts: Hussain chased and caught a burglar that he found in his house, then beat the burglar with a cricket bat.
- Element: Excessive force
- Legal principle: This was not self-defence because the violence was used purely as retribution. The burglary was over and no one was in immediate danger.
R v Oye (2013)
- Facts: The defendant was arrested after behaving oddly in a café. He threw plates at police officers and fought with them when arrested.
- Element: Psychological characteristics are not relevant
- Legal principle: Self-defence was rejected, but an insanity plea was allowed. Mental illness affecting perception of reality should be dealt with through insanity, not self-defence.
R v Taj (2018)
- Facts: The defendant fatally wounded a victim who he wrongly believed was a terrorist about to plant a bomb. The defendant had a history of drug abuse and mental illness and was under the influence at the time.
- Element: Mistaken use of self-defence while intoxicated
- Legal principle: The trial judge withdrew the defence from the jury and the Court of Appeal upheld the murder conviction, rejecting mistaken self-defence based on intoxicated perception.
Duress by threats
Purpose and scope of the defence
Duress by threats is a common law defence whereby someone commits a crime because they were subject to a threat of death or serious injury. The entire definition has evolved through judicial decisions rather than statute.
The defence operates where a defendant argues they were forced to commit a crime due to a direct threat aimed at themselves or others. It is deemed a credible defence because it is 'founded on a concession to human frailty' - recognising that a person's will can be overcome by serious threats.
The key point is that if the defendant had not been threatened, they would not have committed the offence. The defendant does not deny committing the crime but argues they were forced into doing it.
Critical Limitations: This defence is available to all crimes except:
- Murder
- Attempted murder
- Probably treason
Additionally, this defence is rarely successful. Courts are reluctant to believe that defendants truly had no choice but to commit a crime and could not have walked away or sought help from authorities.
Definition and rules
The legal requirements for duress by threats have developed through case law over many years. To establish the defence, several elements must be satisfied.
1. The Graham test (1982)
The Two-Part Test: The starting point is the test established in Graham (1982), both parts of which must be satisfied:
First limb (subjective): Was the defendant compelled to act because they reasonably believed they had a good reason to fear death or serious injury?
Second limb (objective): Would a sober person of reasonable firmness, sharing the same characteristics as the defendant, have acted in the same way?
2. Type of threat
There must be a threat of death or serious injury (grievous bodily harm). Lesser threats are insufficient:
- A threat of serious psychological injury will not suffice - Baker (1997)
- The threat must be convincing, meaning a person of reasonable firmness with the defendant's characteristics would have given in - Howe (1987)
- The threat must be objectively reasonable and subjectively genuine - Hasan (2005)
3. Relevant characteristics
When considering whether a reasonable person with the defendant's characteristics would have responded similarly, certain characteristics may be relevant while others are excluded:
- Pregnancy, serious physical disability or recognised mental illness may be relevant
- Age and gender will be taken into account
- Low IQ will not be considered - Bowen (1996)
4. Combination of threats
There can be a combination of threats, but a threat of death or serious injury must be present and play a major part in the defendant's rationale for committing the crime.
5. Who can be threatened
The threat can be directed at:
- The defendant themselves
- A close family member of their immediate family
- People the defendant is responsible for - Wright (2000)
6. Safe avenue of escape
If there is a safe avenue of escape, then this must be pursued. However, there may be exceptions to this rule - compare R v Gill (1963) with R v Hudson and Taylor (1971), where young witnesses who gave false evidence under threat were allowed the defence even though police protection was theoretically available.
7. Imminence
The threat must be effective and operational when the defendant carries out the crime. The threat of death or serious harm must be 'an imminent danger of physical injury' - Quayle (2005). This means the threat must be immediate or almost immediate - Hasan (2005).
8. Nexus requirement
There must be a nexus (connection) between the crime nominated by the threatener and the crime actually committed - Cole (1994). The defendant cannot choose to commit a different crime from that demanded and still claim duress.
9. Voluntary association
The defence will usually fail if the defendant voluntarily associates with people who are known to make threats, for example, criminal gangs or terrorist organisations - R v Sharp (1987) and R v Shepherd (1987).
Reform proposals
The Law Commission has examined potential reforms to duress in relation to murder charges:
In the 2005 Consultation Paper, 'A New Homicide Act', the Law Commission suggested that duress should be a partial defence to murder. However, when the Law Commission reported in 2006, they recommended it should be a full defence to murder and attempted murder.
A 2008 Ministry of Justice Report, 'Murder, Manslaughter and Infanticide: Proposals for Reform of the Law', made no specific reference to duress by threats in relation to murder, effectively ignoring the earlier Law Commission recommendations. This means the law remains unchanged.
Key cases on duress by threats
R v Howe (1987)
- Facts: Howe was party to the torture and killing of a man. He later participated in another killing while acting alone. He claimed he had been threatened to do so.
- Element: Availability to murder
- Legal principle: The defence was refused for murder. The House of Lords held that one person's life is not worth more than another's, so duress cannot justify taking an innocent life.
R v Gotts (1992)
- Facts: Gotts, aged 16, was threatened by his father into stabbing his mother in an attempt to kill her.
- Element: Availability to attempted murder
- Legal principle: There is no defence of duress to attempted murder, extending the Howe principle.
R v Valderrama-Vega (1985)
- Facts: The defendant imported cocaine after being threatened with exposure of his homosexuality, death and financial ruin.
- Element: Type of threat
- Legal principle: All threats can be considered by a jury, but there must be a threat of death or serious injury present. Other kinds of threat alone are insufficient.
R v Wright (2000)
- Facts: Wright was arrested with cocaine but claimed she possessed it because her boyfriend had been threatened.
- Element: Who can be threatened
- Legal principle: The persons to whom threats may be made include those outside the defendant's immediate family, extending protection to others for whom the defendant feels responsible.
R v Graham (1982)
- Facts: Graham lived with his wife and his homosexual lover. Graham helped his lover kill his wife, claiming he was frightened of his lover.
- Element: Test for suitability of defence
- Legal principle: The court created the two-part Graham test of general suitability for duress defences.
R v Hasan (2005)
- Facts: Hasan associated with a violent drug dealer and was threatened into carrying out a burglary and robbery.
- Element: Imminence
- Legal principle: The threat must be, or be believed to be, immediate or almost immediate. The defendant's voluntary association with criminals also defeated the defence.
R v Cole (1994)
- Facts: Cole robbed a building society to repay a debt after he and his family were threatened.
- Element: Nexus
- Legal principle: Cole chose this course of action to repay his debt, but there was no direct threat to commit robbery. There was no nexus between the threat and the crime committed.
R v Batchelor (2013)
- Facts: Batchelor claimed he had been threatened by armed men over a period of time to repay money they said was owed.
- Element: Failure to seek police protection
- Legal principle: The defendant could have sought police protection over a period of two and a half years, so the threat was not imminent or immediate.
R v Brandford (2016)
- Facts: Brandford was charged with conspiracy to sell class A drugs. She argued her boyfriend had been threatened by a third party that 'something bad would happen to him' unless he transported drugs, and she did it instead to protect him.
- Element: Indirect threats of violence or death
- Legal principle: The Court of Appeal stated that indirect threats could be valid but agreed with the trial judge's rejection of the defence. The words were too vague, lacked immediacy, and she had ample time to contact police.
Duress of circumstances (necessity)
Scope and definition
Duress of circumstances is a common law defence whereby someone commits a crime because of the circumstances in which they found themselves. Most of its definition is based on judicial decisions rather than statute.
This defence is sometimes referred to as the defence of 'necessity'. In Shayler (2001), Lord Woolf CJ stated that the distinction between necessity and duress of circumstances had largely been 'ignored and blurred by the courts' and the two concepts were essentially the same defence.
Key Distinction: The key difference from duress by threats is that with duress of circumstances, the defendant was forced to react due to the circumstances they found themselves in, rather than from a direct threat of death or serious injury made by another person.
This defence has evolved to compensate for the restrictive nature of duress by threats, allowing defendants to argue they faced an emergency situation requiring immediate action.
The legal test
In Re A (Children) (Conjoined Twins: Surgical Separation) (2001), the Court of Appeal approved a comprehensive definition of necessity:
Necessity Definition: An act, which would ordinarily be considered a crime, but may excuse the defendant if they can show that:
- It was done to avoid consequences which could not otherwise be avoided, and if they had been followed would have inflicted inevitable and irreparable evil upon themselves or others
- No more was done than was reasonably necessary
- The evil inflicted was not disproportionate to the evil avoided
In addition to this definition, the two-part Martin test must be satisfied:
First part: From an objective point of view, the accused acted reasonably and proportionately to avoid a threat of death or serious harm
Second part: The same two-part Graham test applies (as used for duress by threats)
Originally, this defence was raised primarily against driving offences, but it has been extended on a case-by-case basis to other criminal conduct where defendants face emergency circumstances.
Key cases on duress of circumstances
R v Willer (1986)
- Facts: Willer drove on a pavement to avoid being attacked by youths. There was no explicit threat to carry out a crime.
- Element: Origins of the defence
- Legal principle: The jury should be allowed to consider some type of duress in such emergency circumstances.
R v Conway (1988)
- Facts: Conway drove dangerously fast after he thought he and his passenger had been shot at.
- Element: Origins of the defence
- Legal principle: Duress of circumstances was available if, from an objective point of view, the defendant was acting to avoid a threat of death or serious injury.
R v Martin (1989)
- Facts: Martin drove while disqualified because his wife threatened suicide if he did not take their son to work.
- Element: Establishing the test
- Legal principle: The Court of Appeal adapted the two-part Graham test to create the Martin test for duress of circumstances.
R v Pommell (1995)
- Facts: Pommell was found with a gun at his house, claiming he had taken it from a dangerous individual and intended to hand it to police.
- Element: Extent and availability
- Legal principle: The Court of Appeal held that whether duress of circumstances applied was a matter for the jury to decide based on all the circumstances.
DPP v Davis (1994)
- Facts: Davis drove while intoxicated to avoid being attacked.
- Element: Extent and availability
- Legal principle: The convictions were quashed on appeal. Duress of circumstances was available as a defence to the driving offence.
R v Cairns (1999)
- Facts: A victim threw himself onto the bonnet of Cairns' car. Cairns warned the victim to get off, then drove forward and braked. The victim fell off and was seriously injured.
- Element: Extent and availability
- Legal principle: There was a reasonable perceived threat of death or serious injury to the driver, and the defence of duress of circumstances was allowed.
Evaluation of necessity defences
Self-defence remains a complicated and controversial area of law. With its roots and development largely in common law, any use of self-defence will always generate debate, particularly in householder cases where there is public sympathy for people defending their homes.
The difference between duress of circumstances and the defence of necessity can seem confusing to students and practitioners alike. The two defences have evolved somewhat haphazardly as defence lawyers have sought to exploit perceived shortcomings in the common law that have not been addressed by Parliament through statute.
The restriction preventing duress from applying to murder charges has been criticised by the Law Commission, but Parliament has not acted on reform proposals. This means that defendants facing threats to their own life or their family's lives cannot rely on duress if they kill to save themselves, which some argue is morally problematic.
Key Points to Remember:
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Self-defence requires two elements: the use of force must be necessary (subjective test) and the degree of force must be reasonable (objective test)
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Householders can use disproportionate force when defending against intruders, but not grossly disproportionate force
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Duress by threats is not available for murder, attempted murder or probably treason
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The Graham test applies to duress by threats: (1) reasonable belief of death/serious injury threat, and (2) would a reasonable person of reasonable firmness have acted the same way
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Duress of circumstances differs from duress by threats because it involves reacting to emergency circumstances rather than direct threats, and uses the Martin test alongside Graham
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There must be a nexus between the crime threatened and the crime committed for duress by threats to succeed
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Mistaken self-defence is allowed if the belief was honestly held, but not if the mistake was caused by voluntary intoxication