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DEFENCES Even if the prosecution prove the AR and MR of an offence, D may still be able to argue that he has a defence. SELF-DEFENCE Requirements of the defence are: (i) D was (or believed he was) facing an unjust threat from V; (ii) D used a level of force against the threat (or threat as he believed it to be) that was reasonable in the circumstances. s.3 Criminal Law Act 1967 (1) "A person may use such force as is reasonable in the circumstances in the prevention of crime, or in effecting or assisting in the lawful arrest of offenders or suspected offenders or of persons unlawfully at large." (2) "Subsection (1) above shall replace the rules of the common law on the question when force used for a purpose mentioned in the subsection is justified by that purpose." The defence was further clarified in the following statute. Although, NB, in Keane  (see below) the CA made clear that the statute does not change the law, rather it sets out the existing position in statutory terms --- it "does not exhaustively state the law of self-defence, but it does state the basic principles." s.76 Criminal Justice and Immigration Act 2008 s.76(2) --- Statute applies to the defences of: (i) self-defence; (ii) defence of property; (iii) use of force in prevention of crime or making arrest. s.76(3) --- "The question whether the degree of force used by D was reasonable in the circumstances is to be decided by reference to the circumstances as D believed them to be. s.76(4) --- Where D claims to have a particular belief about the circs., "the reasonableness or otherwise of that belief is relevant to the question whether D genuinely held it" but if it is determined that D genuinely held it, then D is entitled to rely on that belief whether or not: "(i) it was mistaken, or (ii) (if it was mistaken) the mistake was a reasonable one to have made." s.76(5) --- s.4 does not mean that D can rely on a mistaken belief attributable to voluntary intoxication. s.76(5A) --- In 'householder cases' (a case where D uses force against a trespasser in a dwelling) the "degree of force used by D is not to be regarded as having been reasonable in the circumstances as D believed them to be if it was grossly disproportionate in those circumstances." s.76(6) --- in 'non-householder cases' "the degree of force used by D is not to be regarded as having been reasonable in the circumstances as D believed them to be if it was disproportionate in those circumstances."
s.76(6A) --- For the purposes of s.76(3) (reasonableness of force used by D), "a possibility that D could have retreated is to be considered ... as a factor to be taken into account, rather than as giving rise to a duty to retreat." s.76(7) --- For the purposes of s.76(3): the following considerations should be taken into account: (i) "a person acting for a legitimate purpose may not be able to weigh to a nicety the exact measure of any necessary action; (ii) evidence of a person's only having done what the person honestly / instinctively thought was necessary for a legitimate purpose constitutes strong evidence that only reasonable action was taken by that person for that purpose" Although note that these considerations are not exhaustive. s.76(8F) --- a "'building' includes a vehicle or vessel." i.e. so applies to caravans / houseboats. To what crimes is self-defence a defence? This was a topic of debate, but now it is clear that the defence can be relied upon in relation to any offence (not just crimes of violence)
? Morris : CA held a taxi-driver could rely on s.3 CLA when he engaged in dangerous driving in order to prevent a passenger running off without paying. REQUIEMENTS OF THE DEFENCE From Martin (Tony )
1. V must pose an unjustified threat
2. The use of force must be necessary
3. The degree of force must be reasonable
4. The D must be acting in order to defend himself or another or property.
1. V must pose an unjustified threat V must pose a risk to D or someone else. However, this requirement has been cast into doubt in the following: Hitchens 
? Facts: D was charged with an assault on Kathleen Brown. He argued that he assaulted her in order to prevent her allowing a man into her flat, who D believed would assault him. The judge ruled D could not rely on self-defence where the assault was against an innocent person in order to prevent an attack against a third party.
? CA (Gross LJ): The defences are "capable of extending to the use of force against an innocent third party to prevent a crime being committed by someone else." Gross notes that "this rule has a greater scope for operation where it was certain that a crime would be committed immediately if action was not taken." Conversely, where there is a low-likelihood of a crime being committed / the crime would be committed sometime in the future, the rule will be hard to apply. However, in this case, there was little risk of a crime being committed and V was merely doing what she was entitled to do. If D had been afraid of a crime being committed, he had time to call the police. o Gross notes that circs. in which version of the defence could apply will be rare, but gives examples: (i) "A police constable bundles a passerby out of the way to get at a man he believes about to shoot with a firearm or detonate an explosive device; (ii) Y seeks to give
Z car keys with Z about to drive. X, believing Z to be unfit to drive through drink, knocks the keys out of Y's hands and retains them." Herring: the CA have got this wrong. In the two hypothetical cases, the correct defence would be duress. The case threatens to undermine the line the law draws between duress and self-defence. There is no doubt that the defence applies whether the threat is being posed to the D or to another person / property. [Note: another argument is that this lets in the defence of necessity to murder in through the back door --- i.e. the only circumstances in which it would be reasonable for D to kill an innocent V would be where it was necessary.]
2. The use of force must be necessary Must be shown that it was necessary to use reasonable force. This means that it must have been reasonable for D to use force, rather than to attempt to escape the situation in some way. NB: D can take 'pre-emptive' action if it was reasonable to do so: AG's Reference No. 2 of 1983 
? Facts: D was a shopkeeper. His shop was in the centre of extreme riots --- PS600 worth of damage was done to his shop and PS400 worth of his goods were stolen. After this attack he remained in his shop without sleep and in fear of further attack. He made 10 petrol bombs to protect himself in case he was subject to further attacks. He was charged with offences under the Explosive Substances Act 1883. He was acquitted, but the AG referred the question as to whether self-defence could be used to cover preparing for attack.
? CA (Lane CJ): The defence could be allowed for offences based on possession in preparation of attacks provided the possession ceases when the danger of attack is no longer imminent. "In our judgment a defendant is not left in the paradoxical position of being able to justify acts carried out in self-defence but not acts immediately preparatory to it. There is no warrant for the submission on behalf of the Attorney General that acts of self-defence will only avail a defendant when they have been done spontaneously."
3. The use of force must be reasonable Normal cases: D can use the defence only if the level of force was reasonable in the face of the threat as perceived by D. Question is objective --- would a reasonable person see the level of force as appropriate. However, the situation is measured as D believed it to be. Some guidance (NB: this was decided before the split in householder / non-householder cases). R v Martin (Anthony) 
? Facts: D lived alone on an isolated farm, which was subject to numerous break ins. The Vs broke in and D shot one dead with a shotgun. D was convicted of murder. On appeal, counsel sought to introduce new evidence that D was suffering from a psychiatric condition which showed: (i) there was diminished responsibility; (ii) he was more likely to genuinely believe that he was about to be attacked than the ordinary person.
? CA (Woolf CJ): the disorder could not be considered for self-defence, but there was evidence of DR, so the murder conviction was quashed.
o What was the reasonable amount of force? "It cannot be left to D to decide what force it is reasonable to use because this would mean that even if D used disproportionate force but he believed he was acting reasonably he would not be guilty of any offence." Rather, it is for the jury to decide the amount of force "which it would be unreasonable to use in the circumstances in which they found D believed himself to be in." o On whether mental illness can be taken into account: He recognises that "too generous an approach as to what is reasonable could result in an exorbitant defence ...
We would accept that the jury are entitled to take into account in relation to self-defence the physical characteristics of the defendant ... [It is not] appropriate, except in exceptional circumstances which would make the evidence especially probative, in deciding whether excessive force has been used to take into account whether D is suffering from some psychiatric condition." The level of force applied can be greater than that threatened (e.g. killing in defence to rape), but where the level of force is far greater, there will be no defence. NB: it's not an exact science --- it can't be weighed "to a nicety." Householder cases (s.76(5A)): Collins interprets s.76(5A) as imposing a two-part test for homeowner cases: (i) the use of force must not be disproportionate in the circs. as D believed them to be; (ii) the use of force must be reasonable in the circs. as D believed them to be. R (Collins) v SS Justice 
? Facts: C, a trespasser, was confronted by one of the householders (A), who forced him into a headlock and held him there until the police arrived --- as a result, C suffered serious injury. The CPS decided not to prosecute A on the grounds that a jury would find that A acted in selfdefence, particularly given the 'householder' provisions in the CJIA 2008 applied. C applied for judicial review, claiming that s.76(5A) was incompatible with s.2 of the ECHR (right to life includes positive obligation to put in place criminal law provisions to deter the commission of offences against the person).
? High Court (Leveson): There was no breach of the ECHR because, although there would be householder cases where the degree of force was reasonable despite being disproportionate, this did not diminish the capacity of UK law to deter offences against the person. o On s.76(5A): The householder provisions provided the context in which the question of what was reasonable was to be approached --- although s.76(5A) excluded a degree of force which was grossly disproportionate from being reasonable in a householder case, it did not direct that any degree of force that was less than grossly disproportionate was reasonable. o Proposed test: two separate questions in a householder case: "(i) whether the degree of force which D used was grossly disproportionate in the circumstances as D believed them to be.; and if not (ii) whether the degree of force which the D used was reasonable in the circumstances as he believed them to be. Only if it was both not grossly disproportionate and reasonable does he have a defence."
4. D must be acting in order to defend himself or another or property This intersects with the Dadson principle --- D cannot rely on the justifying circumstances of his / her actions of which he
or she is not aware. If D was acting in self-defence, but did not believe he was then he will have no defence.
Ds who think they are being attacked, but are not?
Jury must ask whether, on the facts as perceived by D, the level of force was reasonable. This was established in the following cases: Williams 
? Facts: M saw a youth (Y) rob a woman in the street. M caught him again and knocked him to the ground. D, who had only seen the latter stages of the incident, was told by M that M was arresting Y for mugging a woman. M said he was a police officer, which was untrue, so could not produce a warrant card when D requested it. D then assaulted M by punching him in the face and was charged with assault occasioning ABH. D's defence was that he honestly believed Y was being unlawfully assaulted by M.
? CA: if D was acting under a mistake as to the facts, he was to be judged according to his mistaken view of the facts --- it did not matter if the mistake was, objectively, reasonable. The reasonableness of D's belief was evidence as to whether the belief was truly held by him. "The reasonableness or unreasonableness of the defendant's belief is material to the question of whether the belief was held by the defendant at all. If the belief was in fact held, its unreasonableness, so far as guilt or innocence is concerned, is neither here nor there. It is irrelevant." Beckford 
? Facts: D, a police officer, was charged with murder. The prosecution claimed that D and another officer had chased the deceased, V, who was unarmed --- eventually shooting him dead when his hands were raised and he was begging them not to shoot. D claimed that he had been sent to a house to investigate a report that V was a dangerous gunman terrorising someone there. On arrival they saw V running away with what appeared to be a gun --- D claimed that V fired at the officers while they were chasing V, the police then returned fire and they killed V.
? PC (Lord Griffiths): the prosecution had to prove that the violence used by D was unlawful --- therefore, if D honestly believed the circumstances would justify his use of force to defend himself or another from attack, and the force used was reasonable to resist, he was entitled to be acquitted. "a genuine belief in facts which if true would justify selfdefence [is]a defence to a crime of personal violence because the belief negativesthe intent to act unlawfully. Their Lordships therefore approve the ... judgment of Lord Lane C.J. in. Williams (Gladstone) as correctly stating thelaw of self-defence." Self-induced self-defence If D caused the attack, then he may not be able to rely on self-defence --- the question for the jury is whether D's use of force was reasonable in light of the fact that he had instigated the fight:
? Facts: K had an altercation with a girl at a petrol station, the girl's friend (V) stepped in to intervene and calmly spoke to K. V then turned away, at which point K said "what are you going to do about it." V turned back and made an aggressive motion, at which point K punched him in the face. Issue: is the defence was available when D was the initial aggressor.
? CA (Hughes LJ): D was unable to rely on self-defence. Where D had either started the fight with V, or entered it willingly, that would always be a bar to self-defence. Self-defence could arise in the case of the original aggressor, but only where the violence offered by the victim was so out of proportion that the roles were effectively reversed. The question for the jury in such a case should be whether "the tables had been turned". No separation between prevention of crime and self-defence (two limbs of s.3 CLA 1967) Clegg 
? Facts: D, a solider, was with a patrol in N. Ireland attempting to catch joyriders. A stolen car approached at speed and D fired three shots into the windshield and one into the back of the car as it drove away, the last shot killed a passenger. D was charged with murder. D was convicted
--- although the first three shots were fired in self-defence, the last was not.
? HL (Lloyd): where D used greater force in self-defence than was necessary in the circumstances, he was guilty of murder. There was no distinction to be drawn between the use of excessive force in self-defence and in the prevention of crime. It made no difference that the person exercising force was a soldier / police officer on duty. NB: 'acting under orders' is no defence in English law, but in extreme cases it could form the basis of duress or lack of MR. NECESSITY The courts have been consistent in denying a general defence of necessity (i.e. an argument that the D did the 'lesser of two evils'; they were in a situation where whatever they did there would be harm caused and the D took the option that caused the least harm). This is clear from:
? Kitson : a drunk man who had fallen asleep in the back of his car awoke to find the car moving down a hill, and he steered the car to safety, avoiding any injury. He was still convicted of a drink-driving offence. The fact that the man was acting in a way society would have wanted him to act was irrelevant. [Note: if criminal law is about: (i) sanctioning undesirable behaviour; (ii) deterring others from committing serious crimes, then how come we don't recognise a general defence of necessity (cf. slippery slope comments in Nicklinson).
? Dudley and Stephens : C and S, along with a boy of 17-18 (V), were cast away in a storm in an open boat, more than 1,000 miles from land. After 18 days without food, D + S proposed casting lots to see who would be put to death to save the rest. They subsequently decided to kill V. On the 20th day, D, with S's assent, killed V. D + S survived by eating V. Queen's Bench (Coleridge CJ): there was no proof of any such necessity as could justify D +
S killing V --- they were guilty of murder, despite the fact that they believed killing V was the only chance of survival. To hold otherwise would be "the absolute divorce of law from morality."
The exact ratio of this decision has been much debated --- in Howe it was held to be the general proposition that necessity is no defence to murder. In Re A the majority of the HL gave it a narrower meaning (see below). THE LIMITED DEFENCE OF NECESSITY AT COMMON LAW Despite a denial of a general defence to necessity, in fact a limited defence of necessity is recognised at common law and in some statutes:
1. Where D damages / steals property in the public interest (e.g. pulling down a house to create a fire-break).
2. Where D damages the D's property / interferes with another's property in order to save his own person / property (e.g. in order to prevent the spread of fire onto his own land)
3. Where action is taken for the benefit of another person, where that person is unable to consent. In Re F (Mental Patient: Sterilisation) this doctrine was relied up on to authorise the sterilisation of a mentally ill woman; the HL found that the operation would be in her best interests and that she was unable to consent --- necessity could therefore be relied upon. Lord Goff also suggested that necessity could justify pushing a V out of the way of an oncoming car (although the push would still be a battery). This category was limited in that case to situations in which V could not consent; thus where a patient actively refuses to undergo an operation, you can't make them (even if it would be in their own best interests). Additionally, a very limited category of necessity as a defence to murder was recognised in the following case. Although, the CA recognised the defence, it is difficult to ascertain an underlying principle. Re A (children) : Facts: the case involved conjoined twins (Mary and Jodie) --- the weaker, Mary, dies if an operation is performed, both die if it is not. The parents are unwilling to agree to the operation as they are Roman Catholic. The doctors appeal to the court for a declaration that the operation can go ahead.
? Key question: Do the doctors recognise that death or serious harm will be virtually certain, barring some unforeseen intervention, to result from carrying out this operation? If so, the doctors intend to kill or to do that serious harm even though they may not have any desire to achieve that result. It is common ground that they appreciate that death to Mary would result from the severance of the common aorta. Unpalatable though it may be to stigmatise the doctors with "murderous intent", that is what in law they will have if they perform the operation and Mary dies as a result.
? CA: although the doctors did intend (on a Woollin definition) to kill Mary, they had a defence of necessity. Brooke LJ identified three requirements that must be found for there to be a defence of necessity (discussed below; see Rogers article and Herring discussion). Rogers, Necessity, Private Defence, and the Killing of Mary
? Before Re A (Children) a defence of necessity had to be presented as a plea that the harm done was in the "best interests" of the victim, and in circumstances where the victim's consent (if it could be obtained) would justify the action. The decision in Re A (Children) seems to add a new, utilitarian, defence of necessity to that which was recognised in Re F.
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