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Gurina Kaur

The term self-defence vocalises the notion of an individual using reasonable force in order to defend oneself or another;[1] arising through both common and under statutory law: Criminal Law Act[2] - S.3 states that ‘a person may use such force as is reasonable in the circumstances in the prevention of crime;’[3] recently clarified under s.76 of the Criminal Justice and Immigration Act 2008 (CJIA).[4] There are circumstances in which the use of force by a member of security against another may be justified, giving no rise to criminal liability and only providing justification where the defendant’s (D) offence involved the use of force; commonly applied as a defence to murder.[5] Though, each case will differ and will be judged on its own facts; Palmer v R highlights the basic principles of self-defence.[6]


Initially, Isambard Security Ltd (ISL) must be informed that to plead self-defence, a person must believe they are subject to unlawful violence and respond using reasonable force: the legal burden is on the prosecution to prove beyond reasonable doubt that the elements of the defence are not satisfied.[7] S.76(3) provides that the question whether the degree of force used by D was reasonable in the occurrences is to be decided by reference to the circumstances as D believed them to be:[8] the subjective element.[9] Here, a security guard will honestly believe that the use of force was necessary on the facts: removing someone off premises; satisfied even where they are wrong, and their mistake is unreasonable. Essentially, the jury will decide if one did what he ‘honestly and instinctively’ felt was necessary in the circumstances[10] — which is true even if D was mistaken in his belief; as in Gladstone Williams:[11] D was to be judged on the facts as he saw them; D had made a genuine, honest mistake.[12]  Furthermore, the law accommodates mistaken belief in self-defence as an acknowledgement; however, case law has limited the availability of self-defence if the use of force is based on intoxication[13]. This is not applicable for a security firm as intoxication implies a lack of professionalism.


When determining whether the use of force was necessary, it is significant to consider the use of force to prevent an attack that is feared, but has not yet taken place. Lord Griffith in Beckford stated: ‘A man about to be attacked does not have to wait for his assailant to strike the first blow; circumstances may justify a pre-emptive strike;’[14] exhibiting the idea that the defence could apply where D uses force to ‘ward off or prevent attack’ as long as she honestly believed attack was ‘imminent’— a requirement interpreted narrowly.[15] This will ensure that a member of the security is performing their duty accurately through prioritising ones’ safety.


A further issue upon the availability of self-defence: a duty to retreat. There is no rule of law that a person under threat of attack has to retreat or run away when under threat of force; giving rise to D’s right to autonomy and ensuring that the security team perform their profession accurately.[16] Though, in Julien: retreating was seen as an obligation of establishing this defence; the defender must ‘demonstrate by his actions that he does not want to fight.’[17] A failure to retreat is merely a factor to be taken into account when determining the reasonableness of D’s conduct.[18] However, it is a legal requirement in some jurisdictions that a threatened person cannot harm another in self-defence, if it is possible to retreat to a place of safety. In Bird, an attempt to retreat demonstrated that D was unwilling to fight, negating any suggestion of retaliation or revenge.[19] Therefore, the jury must decide whether D had acted reasonably defending himself.  

Correspondingly, it is now clear that a security firm may appeal to the defence even where they instigated the violence. The only exception to this is where one has consciously manipulated V into attacking them in order to retaliate in ‘apparent’ defence.[20] In these situations, confirmed in Rashford,[21] D’s force will not satisfy the necessity element.[22] Furthermore, it is also not necessary for one to use force against another party who is acting in lawful self-defence: though, this rule is not absolute.[23]


The objective element focuses upon a reasonable degree of force[24] — the threat must be unjustified.[25] The force used by the security team must be ‘such force as is reasonable in the circumstances’ if it is to be lawful.[26] The general rule is that the force used must be no more than necessary: it must be proportionate to the threat. If reasonable or proportionate, even if it equated to more force than threatened, the defence will satisfy, and D will be acquitted.[27] Under s.3, D’s intervention will be justified provided reasonable force is used.[28] Though, if a jury should find that force was excessive, the defence will fail; if there was an entitlement to use some force, this may be thought to accentuate culpability to an extent.[29]  

The current law combines these approaches: the degree of force used was objectively reasonable based on the subjective facts as D believed them to be. Thus, where a security guard mistakenly believes a student is about to shoot them, responding by stabbing V, the question for the jury is whether the stabbing was objectively reasonable based on D’s belief — the focus is upon the degree of force not the degree of harm caused. When assessing the objective reasonableness, the jury will also take account of the circumstances surrounding the use of that force.[30] This involves a margin of appreciation for D; a rule expressed through the courts:[31] ‘it will be recognised that a person defending himself cannot weigh to a nicety the exact measure of his necessary defensive action.[32]


In conclusion, a right to self-defence remains a rationale, assuming any individual will have the right to expect absolute safety. The reasonableness will remain a matter for the jury; where the defendant kills using a reasonable proportionate amount of force, the complete defence of self-defence will be available.


Written by Gurina Kaur