Citizen's arrest is the informal name for an arrest made by a person who is not a constable. In England and Wales, the main modern power is section 24A of the Police and Criminal Evidence Act 1984 (PACE). The statute calls it arrest by "a person other than a constable".
The power is deliberately narrower than a police officer's power of arrest. It is mainly for serious or potentially serious offences, urgent situations, and cases where waiting for a constable is not reasonably practicable. It can apply to theft, including shop theft, because theft is an either-way offence.
England and Wales
Section 24A of PACE allows a person other than a constable to arrest without warrant in two broad situations:
- Where someone is in the act of committing an indictable offence.
- Where an indictable offence has been committed and the person making the arrest has reasonable grounds for suspecting the person to be guilty of it.
It also allows arrest where the person has reasonable grounds for suspecting that an indictable offence is being committed.
The word "indictable" is important. In England and Wales, it includes offences triable either way, not only indictable-only offences. That means theft, burglary, robbery, assault occasioning actual bodily harm, and many other either-way offences can fall within section 24A. Summary-only offences usually do not, unless another statute preserves or creates a relevant power.
Necessity Conditions
Section 24A does not allow a private person to arrest merely because an offence has happened. The arrest must also be necessary for one or more statutory reasons, and it must appear that it is not reasonably practicable for a constable to make the arrest instead.
The necessity reasons are:
- To prevent the person causing physical injury to themselves or another person.
- To prevent the person suffering physical injury.
- To prevent loss of or damage to property.
- To prevent the person making off before a constable can assume responsibility.
These conditions matter in ordinary cases. If police are already present and can deal with the suspect, a private arrest will usually be unnecessary. If a suspect is about to leave before police can arrive, the "making off" condition may be central.
Shop Theft
Shop theft is the clearest everyday example. Theft under section 1 of the Theft Act 1968 is an either-way offence, so a shop worker, owner, or security guard may have a section 24A power where the statutory conditions are met.
Example:
- A shop worker sees a person conceal goods and walk past the tills without paying.
- The worker has direct evidence of theft in progress.
- Police are not already there and cannot make the arrest at that moment.
- The person is likely to leave with the goods before police arrive.
In that situation, section 24A may allow the worker, owner, or security guard to arrest the person and call police. The force used to detain the person must still be reasonable. The power does not make it lawful to punish, humiliate, search beyond lawful authority, or use force after the person is under control.
Low-Value Shoplifting
The Anti-social Behaviour, Crime and Policing Act 2014 made theft from a shop of goods worth £200 or less summary-only for some procedural purposes, while preserving PACE powers that depend on an indictable offence. Home Office guidance expressly described this as preserving powers for shop security staff to make a citizen's arrest.
As at 22 June 2026, section 47 of the Crime and Policing Act 2026 has been enacted but is marked by legislation.gov.uk as prospective. When commenced, it will repeal the low-value shoplifting provisions and section 176 of the 2014 Act, making theft from a shop triable either way irrespective of the value of the goods. The practical result is that the special low-value shoplifting workaround will no longer be needed once section 47 is in force.
Reasonable Force
Section 3 of the Criminal Law Act 1967 allows a person to use force that is reasonable in the circumstances to prevent crime or to effect or assist a lawful arrest. This is separate from the arrest power itself. A person may have a power to arrest but still use excessive force, or may use reasonable defensive force without making an arrest.
Reasonable force depends on the facts as they appeared at the time. Relevant factors include the seriousness of the suspected offence, whether the suspect was violent, whether weapons were present, the risk of escape, the size and strength of those involved, the availability of police, and whether the person detained had stopped resisting.
Examples of force that may be reasonable in the right circumstances include blocking a doorway, holding a wrist or arm, guiding a person away from danger, or restraining someone who is actively assaulting another person. Force becomes harder to justify once the person is compliant or the immediate risk has passed.
Practical Examples
Theft from a Shop
A person is seen taking goods from a shelf, hiding them in a bag, and leaving without paying. A shop owner stops them outside the door and calls police. If the owner has reasonable grounds and the person is likely to leave before police arrive, section 24A may apply.
Assault in Progress
A member of the public sees one person punching another in the street. Restraining the attacker until police arrive may be justified as prevention of crime, defence of another person, and, where the offence is indictable or either-way, a section 24A arrest.
Mistaken Identity
A security guard is told by a customer that "someone in a blue coat stole something" and then grabs the first person in a blue coat outside the shop. That is risky. Section 24A requires reasonable grounds. Vague description, poor observation, or guesswork can make the detention unlawful.
Summary-Only Behaviour
Someone is rude, annoying, or causing a minor disturbance that does not amount to an indictable or either-way offence. Section 24A will usually not apply. Calling police, recording evidence, asking the person to leave private premises, or using ordinary civil powers may be more appropriate than attempting an arrest.
Difference from Police Arrest
Police officers have wider statutory powers. Section 24 of PACE allows a constable to arrest for any offence where the statutory conditions are met, including the necessity test in PACE Code G. Section 24A is narrower because it is restricted to indictable offences and requires the additional practical condition that a constable cannot reasonably make the arrest instead.
Private citizens also lack many powers that police have after arrest. A citizen's arrest is normally a short-term detention so police can take over. It is not a power to investigate like a police officer, conduct a general search, transport someone long distances, or hold someone for convenience.
Risks of Unlawful Arrest
An unlawful citizen's arrest can lead to civil or criminal consequences. Possible issues include false imprisonment, assault, battery, theft or damage to property, harassment, public order allegations, and claims for compensation.
The biggest risks are:
- Arresting for an offence outside section 24A.
- Acting on weak suspicion.
- Detaining the wrong person.
- Continuing detention after police could take over or after the justification has ended.
- Using more force than the situation reasonably required.
- Turning a defensive act into retaliation.
Breach of the Peace
Breach of the peace is a separate common law area and should not be confused with section 24A. It can justify intervention in some urgent public order situations, but it is not the same as arrest for an indictable offence under PACE. The safest way to describe section 24A is as a statutory power for specific criminal offences, not as a general power to deal with every disturbance.
Other Jurisdictions
The phrase "citizen's arrest" is used in many countries, but the rules differ. Scotland, Northern Ireland, Canada, Australia, Germany, France, India, and the United States each have their own tests and limits. A rule from one jurisdiction should not be assumed to apply in England and Wales.
See Also
- Police and Criminal Evidence Act 1984
- Reasonable force
- Self-defence in English law
- Theft Act 1968
- Criminal Law Act 1967
References
- Police and Criminal Evidence Act 1984, section 24A
- Interpretation Act 1978, Schedule 1
- Criminal Law Act 1967, section 3
- Criminal Justice and Immigration Act 2008, section 76
- Anti-social Behaviour, Crime and Policing Act 2014, section 176
- Home Office guidance on low-value shoplifting
- Crime and Policing Act 2026, section 47
- Crime and Policing Act 2026 retail crime factsheet
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