Introduction
In criminal law, even where the prosecution can prove both the actus reus and mens rea of an offence, a defendant may still be acquitted if they can successfully raise a defence. General defences are those which, in principle, can apply to any crime, although there are exceptions. They operate to either justify the defendant's conduct, meaning it was not wrongful, or to excuse it, meaning it was wrongful but the defendant is not held blameworthy due to the circumstances. This essay will provide an overview of two significant general defences in the law of England and Wales: self-defence and duress. It will explain the key legal principles governing each defence and highlight some of the restrictions on their availability.
Self-Defence
The defence of self-defence, which also includes the defence of another or the prevention of crime, is a justificatory defence. Its legal basis is found in both common law and statute, specifically section 76 of the Criminal Justice and Immigration Act 2008 (CJIA 2008). The core test for the defence has two elements.
First, the use of force must have been necessary from the defendant's perspective. This is a subjective test, meaning the crucial question is whether the defendant genuinely believed that it was necessary to use force, as established in R v Williams (Gladstone) (1987) 84 Cr App R 299. A defendant can therefore rely on the defence even if their belief was mistaken, provided it was honestly held.
Second, the level of force used must have been reasonable in the circumstances as the defendant believed them to be. This is an objective test, but it is assessed based on the facts as the defendant subjectively perceived them. The law acknowledges that a person under attack cannot be expected to "weigh to a nicety the exact measure of his necessary defensive action" (Palmer v R [1971] AC 814). Section 76(7) of the CJIA 2008 reflects this, stating that evidence of a person acting "honestly and instinctively" in a moment of unexpected anguish is strong evidence that their actions were reasonable. A notable development is the 'householder' provision in section 76(5A), which allows a householder defending themselves from a trespasser to use force that is disproportionate, as long as it is not 'grossly disproportionate'. This has created a different standard for cases occurring in the home, although its practical application remains a point of discussion (Herring, 2022).
Duress
Unlike self-defence, duress is an excusatory defence. It does not justify the crime but argues that the defendant's will was overborne by a serious threat, and therefore they should not be held responsible. The modern test for duress by threats was established in R v Graham [1982] 1 WLR 294 and involves two stages.
The first stage is a largely subjective test: was the defendant compelled to act as they did because they reasonably believed they had good cause to fear death or serious injury? A threat of minor harm or damage to property is insufficient. The second stage is objective: would a sober person of reasonable firmness, sharing the characteristics of the defendant, have responded to the situation in the same way? The House of Lords in R v Bowen [1996] 4 All ER 837 clarified that relevant characteristics could include age, sex, pregnancy, and recognised psychiatric conditions, but not low intelligence or unusual timidity.
The defence of duress is subject to strict limitations. Most significantly, the House of Lords confirmed in R v Howe [1987] AC 417 that duress is not a defence to murder, whether as a principal or an accomplice. This was extended to attempted murder in R v Gotts [1992] 2 AC 412. The reasoning is based on the policy that the law should not permit an individual to choose to take an innocent life to save their own. Furthermore, the defence is unavailable where the defendant voluntarily associated with a violent gang, thereby foreseeing or risking being subjected to compulsion (R v Hasan [2005] UKHL 22).
Conclusion
In conclusion, general defences like self-defence and duress play a vital role in the criminal justice system by allowing for the acquittal of defendants who, despite committing the elements of an offence, are not deemed blameworthy. Self-defence justifies the use of necessary and reasonable force in response to a perceived threat. Duress excuses criminal conduct where the defendant acted under a serious threat of death or personal injury. However, both defences are carefully controlled by the courts to prevent them from being abused. The strict requirements, such as the two-part tests for both defences and the absolute exclusion of duress for murder, demonstrate a legal policy that balances compassion for defendants in difficult situations with the need to protect society and uphold the sanctity of life.
References
Herring, J. (2022) Criminal Law: Text, Cases, and Materials. 10th edn. Oxford University Press.
Palmer v R [1971] AC 814
R v Bowen [1996] 4 All ER 837
R v Gotts [1992] 2 AC 412
R v Graham [1982] 1 WLR 294
R v Hasan [2005] UKHL 22
R v Howe [1987] AC 417
R v Williams (Gladstone) (1987) 84 Cr App R 299
Criminal Justice and Immigration Act 2008, s. 76.
