Citizen's Arrest in the UK: Powers, Limits and Real Risk

A "citizen's arrest" is a real legal power in the UK, not just a phrase from films. It also comes with real legal risk. Get the conditions wrong and the person who tried to help can end up the one facing a claim, or even a prosecution, for false imprisonment or assault.

The Power in England and Wales: PACE 1984, s.24A

Section 24A of the Police and Criminal Evidence Act 1984 ("PACE"), in force since 1 January 2006, gives "any person" a power to arrest without a warrant. It is narrower than most people assume.

The offence must be indictable, meaning it is serious enough to be tried at the Crown Court (this includes offences that can be tried either in the Crown Court or a magistrates' court, not only the most serious "indictable-only" crimes, but it still rules out large numbers of everyday summary-only offences). The person making the arrest must reasonably suspect, or actually witness, the person committing the offence, or reasonably suspect them of having committed it.

Even then, s.24A does not simply switch on. Two further conditions have to be met at the same time.

The Necessity Test: Why Most Attempted Citizen's Arrests Fail It

First, it must not be reasonably practicable for a constable to make the arrest instead. In an age of mobile phones and rapid police response in many areas, this condition is doing real work: if calling 999 and waiting is realistically an option, the practicability condition may not be satisfied at all.

Second, the arrest must be necessary for one of the specific reasons set out in s.24A(4):

• to prevent the person causing physical injury to themselves or to someone else;
• to prevent the person suffering physical injury;
• to prevent the person causing loss of or damage to property; or
• to prevent the person making off before a police constable can take over responsibility for them.

A citizen's arrest made simply because someone was annoyed, or wanted to make a point, without one of these specific necessity reasons being genuinely in play, is not one the statute protects.

What s.24A Does Not Cover

Section 24A(5) expressly excludes offences under Parts III and 3A of the Public Order Act 1986, which deal with stirring up racial hatred and stirring up hatred on grounds of religion or sexual orientation. There is no citizen's arrest power for those offences, however serious the underlying conduct might feel.

More generally, s.24A only ever applies to indictable offences. A great many minor, summary-only offences, low-level public order matters and most driving offences fall outside it entirely, whatever a bystander might think is fair.

The Real Risk: False Imprisonment and Assault

This is the part most often missed. A citizen's arrest is a serious act: it removes someone's liberty. If the conditions above are not actually met, whether because the offence was not indictable, because a constable could reasonably have been called instead, or because none of the necessity reasons genuinely applied, the "arrest" is not lawful. The person who carried it out can potentially face a civil claim for false imprisonment, and if force was used, a claim or even a prosecution for assault.

Unlike a police officer, a private citizen who makes a mistaken arrest generally cannot rely on a defence built around reasonable suspicion in the same protected way an officer can. Security operatives, door staff and shop employees have no special arrest powers of their own; they hold exactly the same citizen's arrest power as anyone else, with exactly the same conditions and exactly the same exposure if they get it wrong.

Northern Ireland: Article 26A

Northern Ireland runs a closely parallel system. The Police and Criminal Evidence (Northern Ireland) Order 1989, Article 26A mirrors the England and Wales power almost exactly: the offence must be indictable, and the arrest must be necessary for the same kind of reason (preventing injury, preventing loss of or damage to property, or preventing the person making off), with the same requirement that it not be reasonably practicable for a constable to act instead. Article 26A should not be confused with Article 26, which is the separate power of arrest held by police officers themselves.

Scotland: Common Law Only

Scotland has never had a statutory citizen's arrest power equivalent to s.24A, and none should be assumed. The position instead rests on common law. A private citizen in Scotland can generally make an arrest only where a genuinely serious crime, of the kind that would ordinarily be tried at a higher level such as the Sheriff Court or High Court, either happened in front of them or was committed against them. Examples of the kind of offence this covers include assault, robbery, housebreaking, theft and drugs offences.

Where an arrest is justified, the person making it should use no more than reasonable and necessary force, and must hand the arrested person over to the police as soon as possible, along with any evidence such as witness details or footage. As in England and Wales, a wrongful or excessive Scottish citizen's arrest can expose the person who carried it out to a civil claim.

What to Do Instead of Attempting an Arrest

In almost every situation, calling the police and giving them a clear, safe description of what happened is the lower-risk course of action. Personal safety comes first: no piece of legislation requires anyone to physically confront a suspect, and few situations genuinely satisfy the narrow necessity conditions above. Where a citizen's arrest is attempted, using witnesses, avoiding more force than is strictly needed, and handing the person to police without delay all reduce, though do not eliminate, the legal exposure involved.

This guide explains the citizen's arrest power in general terms. It is not legal advice, and it is not a substitute for professional advice about an actual incident. Anyone who has made, or been subject to, a citizen's arrest should speak to a solicitor. For related rights, see our guides to self-defence and reasonable force and UK knife laws, or the wider UK Criminal Law hub.