SELF-DEFENCE
DEFINTION: This is a complete defence in criminal law and covers situations that where one may
have to defend oneself, another (as amended by the Criminal Justice and Immigration Act 2008) or
to prevent a serious crime ( s3(1) Criminal Law Act 1967)
SCOPE
Self defence is more commonly used when committing non-fatal offences but can also be used in
cases of murder and property offences.
FORCE
Must be necessary to use force.
S76(1)b CJIA 2008 – asks whether the force used by the D against a person was reasonable in the
circumstrances.
1. Was it necessary to use any degree of force?
2. If so, was the degree of force used proportionate or reasonable to the harm threatened or
the risk to be averted?
MISTAKEN BELIEF
When D is mistaken about the circumstances but is still acting to defend themselves, another or
property on their honestly held view of the facts at the time.
Gladstone Williams set out a two-part test for mistaken belief:
1. D must be judged based on his honestly held view of the facts, even if mistaken
2. D can strike first
HOWEVER, under s76(5) CJIA 2008, D cannot rely on their mistaken belief if they reason they held
the belief because they were voluntarily intoxicated
O’Grady – Drunken mistake can only be used to negate mens rea (and only for crimes of specific
intent) and not to justify an unreasonable use of force in plea of self-defence
PRE-EMPTIVE STRIKE
D can strike first if he honestly believes the force to be in defence of himself or another.
R v Beckford – D was a police officer who killed a suspect which he believed had tried to shoot him
whilst evading arrest, the test to be applied for self defence is that a person may use such force as
is reasonable in the circumstances as he honestly believes them to be in defence of himself or
another. A pre-emptive strike is allowed.
DUTY TO RETREAT
D does not show reluctance to fight to be able to claim self defence.
R v Bird – There is no obligation to show an unwillingness to fight to be able to use the defence.
PROPORTIONATE/REASONABLE FORCE
Whether the force used was reasonable or proportionate is a matter for the jury to decide
considering the circumstances of the case, making the law very subjective.
S76 CJIA 2008 whether force is reasonable in the circumstances:
1. A person acting for a legitimate purpose may not be able to weigh to a nicety the exact
measure of any necessary actions (in the heat of the moment we are not measuring
whether something is reasonable) and
2. That evidence of a person having only done what the person honestly and instinctively
thought was necessary for a legitimate purpose constitutes strong evidence that only
reasonable action was taken by that person for that purpose. (a persons instinctive reaction
is probably reasonable)
DEFINTION: This is a complete defence in criminal law and covers situations that where one may
have to defend oneself, another (as amended by the Criminal Justice and Immigration Act 2008) or
to prevent a serious crime ( s3(1) Criminal Law Act 1967)
SCOPE
Self defence is more commonly used when committing non-fatal offences but can also be used in
cases of murder and property offences.
FORCE
Must be necessary to use force.
S76(1)b CJIA 2008 – asks whether the force used by the D against a person was reasonable in the
circumstrances.
1. Was it necessary to use any degree of force?
2. If so, was the degree of force used proportionate or reasonable to the harm threatened or
the risk to be averted?
MISTAKEN BELIEF
When D is mistaken about the circumstances but is still acting to defend themselves, another or
property on their honestly held view of the facts at the time.
Gladstone Williams set out a two-part test for mistaken belief:
1. D must be judged based on his honestly held view of the facts, even if mistaken
2. D can strike first
HOWEVER, under s76(5) CJIA 2008, D cannot rely on their mistaken belief if they reason they held
the belief because they were voluntarily intoxicated
O’Grady – Drunken mistake can only be used to negate mens rea (and only for crimes of specific
intent) and not to justify an unreasonable use of force in plea of self-defence
PRE-EMPTIVE STRIKE
D can strike first if he honestly believes the force to be in defence of himself or another.
R v Beckford – D was a police officer who killed a suspect which he believed had tried to shoot him
whilst evading arrest, the test to be applied for self defence is that a person may use such force as
is reasonable in the circumstances as he honestly believes them to be in defence of himself or
another. A pre-emptive strike is allowed.
DUTY TO RETREAT
D does not show reluctance to fight to be able to claim self defence.
R v Bird – There is no obligation to show an unwillingness to fight to be able to use the defence.
PROPORTIONATE/REASONABLE FORCE
Whether the force used was reasonable or proportionate is a matter for the jury to decide
considering the circumstances of the case, making the law very subjective.
S76 CJIA 2008 whether force is reasonable in the circumstances:
1. A person acting for a legitimate purpose may not be able to weigh to a nicety the exact
measure of any necessary actions (in the heat of the moment we are not measuring
whether something is reasonable) and
2. That evidence of a person having only done what the person honestly and instinctively
thought was necessary for a legitimate purpose constitutes strong evidence that only
reasonable action was taken by that person for that purpose. (a persons instinctive reaction
is probably reasonable)
