The Law and Using Force against Someone Committing Crime

The law on the use of force against someone committing a crime is very similar to that on the use of force in self-defence. However, unlike the law on self-defence, it has been set out in statute. The Criminal Law Act 1967 states that an individual is entitled to use reasonable force to prevent a crime being committed.

Reasonable Force

The amount of force that will be justified will depend on the circumstances in which it is used. However, in principle almost any level of force may be justified if an individual honestly believed it was necessary to prevent a crime taking place. In deciding whether the amount of force used was reasonable a number of factors will be taken into account, including:

• The seriousness of the crime that an individual was acting to prevent – For example, it is unlikely that any force would be reasonable to prevent a thirteen year old schoolboy stealing a chocolate bar;
• Whether the crime could have been prevented in some other way – perhaps by alerting the police;
• The strength of the individual using force relative to the person committing the crime – If a karate black-belt or a body-builder who works as a bouncer uses force against a weaker person there is a high risk that it will be excessive.

Mistaken Beliefs

When force is used, the individual does not have to have been right in his belief that he was acting to prevent a crime to use this as a defence. The belief does not even have to be objectively reasonable – other people may have thought it was ridiculous. However, the belief must have been honestly held when the force was used.

In a case which came to court in 1987 a man was put on trial for assault. He had beaten up a person who he believed was in the process of attacking or kidnapping someone else. It later turned out that what the man had actually seen was a policeman arresting an offender. The court was satisfied that the man honestly believed he was acting to prevent a crime being committed. Therefore he successfully used this as a defence.

However, people who get the wrong end of the stick will not always have this defence available. If a person only believed they were acting to prevent a crime because they were drunk or under the influence of drugs they will not be able to use this as a defence. In addition, the more unreasonable a belief seems, the less likely a jury or court will be to accept that the individual honestly believed it.

The Use of Force to Protect Property

When an individual takes action to prevent someone damaging or stealing his property, or the property of another person, he is entitled to use force. The amount of force that can be justified to protect property may well be lower than what can reasonably be used to protect human life. If this defence is raised two questions will have to be considered:

• Whether the force was used to protect property from an attack - or the threat of an attack - which would amount to a criminal or unlawful act;
• Whether, given the circumstances as the individual saw them, it would be objectively reasonable to use force in those circumstances.

The Approach of the Crown Prosecution Service(CPS)

The CPS is reluctant to prosecute people who instinctively, and with good intentions, intervene to prevent a crime being committed. When deciding whether a prosecution should be brought, the CPS is likely to consider very carefully all the circumstances of an individual case before making a final decision. Generally speaking it is not considered to be in the public interest to prosecute people who have acted to prevent crime, or to protect themselves or other people. The factors that will be taken into account include:

• Any injuries sustained;
• The seriousness of the crime that was being prevented;
• If the force was excessive, how excessive it was - If the force was only slightly above what would be considered reasonable a prosecution is less likely to follow;
• How the force was inflicted – For example, if an individual used his fists to prevent a crime he is less likely to be prosecuted than if he produced a sawn-off shot gun from under his coat;
• Whether the individual was genuinely acting on the spur of the moment or whether he was acting as a vigilante or for revenge.

The CPS will always try to strike a balance between encouraging people to be responsible citizens and discouraging people from taking the law into their own hands.