Citizen’s Arrest

Business, Legal & Accounting Glossary

Definition: Citizen’s Arrest

Full Definition of Citizen’s Arrest

The concept of a ‘citizen’s arrest’ is most relevant to people employed in quasi-constabulary roles, such as security guards. In general, private security personnel don’t have any greater powers of arrest than any other private citizen. However, English law recognizes a number of circumstances in which one private citizen may lawfully arrest another. This guide describes these circumstances, with examples of how they apply in practice.

Because police officers are themselves, private citizens, the powers of a ‘citizen’s arrest’ also apply to the police; be aware, however, that the police have extended powers of arrest not available to other people, and these powers are increasing.


This article is written for general information only. It does not purport to be exhaustive or authoritative. To the extent that it applies at all, it does so only to England and Wales, since the legal position is somewhat different in Scotland and Northern Ireland. Naturally, an article such as this is no substitute for proper legal advice.

The Fundamentals

Let’s start by looking at some fundamental principles relating to the notion of ‘arrest’, and what makes an arrest lawful or unlawful.

What Is An Arrest?

To arrest someone is to deprive that person of his liberty. Normally the term is used in the sense of law enforcement; to deprive someone of his liberty as part of a crime is more commonly called ‘kidnapping’. It is the fact that a person is prevented from going about his business that forms the essence of an arrest. Simply stating ‘you’re under arrest’ does not, in itself, constitute an arrest. If the person so ‘arrested’ runs away he has not, in law, been arrested at all. To arrest someone requires force or, at least, compulsion.

Certain consequences may follow from an unlawful arrest, as we shall soon see. However, if a person has not, in fact, been arrested then logically such consequences cannot flow. For example, in Goodson v Higson (2001) an off-duty police constable stopped a drunken driver and asked him to hand over his car keys and wait for the police, which he did. At trial, the driver claimed that the arrest was unlawful, as the constable had been off-duty, and had no power to arrest him. The driver claimed, therefore, that the Breathalyzer evidence obtained afterwards was tainted with illegality and should not be admitted. However, the court held that the driver had not actually been arrested at all, since he had not been restrained or put under any compulsion. As a result, because there had not been any arrest to begin with, there could not have been an unlawful arrest.

What Is A Lawful Arrest?

To arrest someone is to deprive that person of his liberty; in English law, this is prima facie unlawful. A person arrested unlawfully is entitled to sue for damages, and to use reasonable force to resist arrest. Force used to carry out an unlawful arrest is also unlawful, and may be a criminal offence. In addition, evidence gathered as a result of an unlawful arrest may be declared inadmissible in court (but one should never base a defence on this possibility alone). To demonstrate that an arrest is lawful, the onus is on the arrestor to show that the circumstances fell into one of the standard situations recognized as allowing for an arrest.

When Is A Citizen’s Arrest Lawful?

There are two situations where a citizen’s arrest without warrant may be lawful: (i) the arrestee has either committed or is in the process of committing an indictable offence; and (ii) the arrestee is ‘unlawfully at large’. Private citizens may also have the power to execute an arrest warrant in certain circumstances. These will each be considered in turn.

Citizen’s Arrest In The Case Of An Indictable Offence

An indictable offence is one that is subject (at least in principle) to trial by jury. So is stealing, say, a potato, an indictable offence? Undoubtedly, as theft, in general, is an offence capable of being tried by jury. Although most minor thefts (shoplifting, for example) are dealt with summarily by magistrates, a person charged with such an offence is entitled to demand a trial by jury in the Crown Court (although the courts discourage this sort of thing).

In addition to theft, indictable offences include the following: homicide, serious and indecent assaults, assault and/or battery, rape, criminal damage, and arson.

It can be very difficult for a person who is not a criminal lawyer to remember which of the hundreds of defined statutory offences fall into the category of ‘indictable offence’ and which do not. The use of the terminology ‘indictable’ in this context has only recently been introduced by the Serious Organised Crime and Police Act (2005) (‘SOCPA’). Consequently, it isn’t particularly clear, at the time of writing, whether the courts will be sympathetic to private citizens carrying out arrests for offences that they ‘honestly’ believed to be indictable but turn out not to be. The previous legislation relevant in this context — the Police and Criminal Evidence Act (1984) (‘PACE’) — used the term ‘arrestable offence’, which in truth was no better defined. Under Pace, the courts generally showed little sympathy for private citizens who failed to appreciate the difference between arrestable and non-arrestable offences.

Consider, for example, a case in which there has been a failure to provide the requisite details to another driver at the scene of a road accident. This is an offence, but not an ‘arrestable offence’, under PACE. In R v Jackson (1985), a man who tried to take the ignition keys from a car that had crashed into his, in order to prevent the owner leaving the scene, was deemed to have executed an unlawful arrest. When the driver drove away, dragging the hapless would-be arrestor down the street, this was held to be self-defence: the attempted ‘arrest’ had been unlawful, and the arrestee was justified in having resisted it. This, despite the fact that he had just provided an obviously false name to the other party.

In short, although most serious crimes amount to indictable offences (e.g., all varieties of theft and offences against the person), there are a whole raft of minor and trivial offences that are not indictable, and for which there is no power of arrest accorded to the private citizen.

According to s 24A of PACE (as amended by SOCPA), a person (call him ‘P’) may lawfully arrest another (call him ‘D’) in the following circumstances: (i) P knows that an arrestable offence has (definitely) been committed, and has reasonable grounds to suspect D committed it; or (ii) P has reasonable grounds for suspecting (at that instant) D to be committing an arrestable offence. However, even if these criteria are met, there are two further requirements for a citizen’s arrest to be lawful: (iii) it is not reasonably practicable for P to instead summon a constable to perform the arrest; (iv) the arrest is necessary to prevent: (a) injury to some person, (b) loss or damage to some property, or (c) D’s running off before a constable may be summoned.

Note that rule (i) is somewhat less clear than might at first seem. For instance, if a store detective finds a customer stuffing a bottle of whiskey into his coat pocket, does this provide him with reasonable grounds for a lawful arrest? Most probably it does, as he only needs reasonable suspicion that the customer is committing an arrestable offence. In this case, the facts would seem to support such a suspicion. Besides, the requisite standard is hardly certainty.

But what if the hypothetical customer is caught outside the shop with a bottle of whiskey in his pocket that he hasn’t actually paid for? Here, there are two options: either an offence (theft or burglary, both ‘arrestable’) has already been committed or it has not been committed at all. How is it possible that an offence might in this instance have not been committed? Well, a charge of theft can only be made if the defendant is shown to have acted dishonestly. Here, the customer may well have placed the bottle of whiskey in his pocket only because there was no room in his shopping basket, and then have merely forgotten to pay for it. If the magistrates can be persuaded to accept this explanation, the customer will then have committed no offence, and ipso facto his arrest will have been unlawful.

On the other hand, if the store detective made his arrest while the customer was in the act of placing the bottle of whiskey in his pocket, this will probably amount to a lawful arrest, even if the customer is never actually charged with anything. This is because Rule (ii) makes it likely that the store detective will be deemed to have had reasonable grounds for suspecting (at that instant) that the customer was committing an arrestable offence. Similarly, if P catches D in the process of forcing open the window of someone’s house, P will likely be considered as having had reasonable grounds for believing D was committing an offence, even if the house actually belonged to D. Although D committed no offence, an arrest by P might in this instance be deemed lawful (even if it is ultimately judged to have been a mistake).

The conclusion, therefore, is this: if one is going to make a citizen’s arrest, there is a better chance of it being lawful if one does so while the suspected crime is in progress than after it has been committed. This may be an odd conclusion, but it was supported by the Court of Appeal in R v Self (1992).

Rules (iii) and (iv) are new provisions introduced into PACE by SOCPA and appear, at first sight, to mark a fairly substantial change in this area of the law. Rule (iii) requires an arrest to be performed by a constable (or any sworn police officer) where ‘reasonably practicable’. However, must it be reasonably practicable in terms of crime prevention? Or reasonably practicable in terms of apprehending the suspect? This is not at all clear, and there isn’t much case-law in this area at present. It certainly seems likely that one cannot now be said to have performed a lawful citizen’s arrest under these new provisions if a policeman was within hailing distance at the time, but it is less clear precisely how a citizen would be expected to deal with, say, finding an intruder nosing around his garden shed with a torch in the middle of the night. This probably isn’t a situation where anyone is in any imminent danger, and it probably is reasonable to simply telephone the police (this, after all, is what most people would be likely to do). So would it be lawful to apprehend the suspect oneself, even if one is satisfied that the prowler is in the process of committing a burglary? This is difficult to say, and lacking further judicial scrutiny of this provision, it is uncertain whether anybody knows. Clearly the intention of the new provision is to prevent people carrying out violent and ill-timed arrests as an alternative to calling the police; this suggests that one would have to be fairly certain that he couldn’t prevent the crime by calling the police.

Rule (iv) provides a relatively short list of circumstances in which a citizen’s arrest may lawfully be performed. However, it probably does not restrict the performance of a citizen’s arrest to quite the degree as one might initially be assumed. This is because the final provision — that it is necessary to prevent the suspect running away — seems to cover most circumstances in which a citizen’s arrest would, in practice, be carried out. If the suspect is willing to wait quietly for the police to arrive, no arrest is even necessary!

A particular problem for private security personnel is that neither PACE nor SOCPA grants the power to make a citizen’s arrest merely on the suspicion that an individual is about to commit an indictable offence. For example, if D is walking around a car park with a set of lock-picks in his hand, and looking greedily into all the posh cars, P might reasonably conclude that D intends to steal one of these vehicles. However, until D begins the process of breaking into an automobile, he can’t be lawfully arrested by a private citizen. On the other hand, D could be arrested by a constable, since PACE provides a specific power of arrest for constables in such circumstances.

Even so, this does not mean that under no circumstances can a citizen’s arrest be effected before a crime is actually in progress. By definition, it is an indictable offence to attempt to carry out an indictable offence, whether or not the offence is, in the end, committed. An ‘attempt’ is ‘any act that is more than merely preparatory’ to committing the offence. Suppose, for example, D has a grudge against P and one day arrives at P’s house with a petrol bomb. If P sees D lighting the explosive outside his house, must P wait until the bomb is actually exploding before apprehending D? It would appear not, since lighting the bomb has got to be ‘more than merely preparatory’ to the act of committing arson. However, in the car theft example, it may well be that the suspect’s act of inspecting cars with a (possible) view to stealing one can hardly be said, with the same degree of certainty, to be ‘more than merely preparatory’ to committing the crime. Here, the security guard would likely have to wait until the thief tries to break into one of the cars before arresting him.

It should be fairly obvious at this point that there are an awful lot of ‘borderline’ cases where it is not at all clear whether or not a ‘citizen’s arrest’ would be lawful.

In sum, a citizen’s arrest by person P against person D is likely to be lawful in the following circumstances: (i) Where an indictable offence has definitely been committed, and P has reasonable grounds to suspect D of being the perpetrator. (ii) Where P has reasonable grounds for suspecting that D is in the act of committing an indictable offence, even if it later turns out that D did not commit any offence at all. (iii) Where P has reasonable grounds for suspecting that D has done something that is ‘more than merely preparatory’ to committing an indictable offence. Note: Each of these situations is subject to the proviso that P be certain that simply calling the police instead is not a ‘reasonably practicable’ way of dealing with the situation.

On the other hand, a citizen’s arrest is unlikely to be lawful in the following circumstances: (i) Where P suspects that D earlier committed an indictable offence, and it later turns out that he didn’t. (ii) Where P believes that D is about to commit an indictable offence, but D has thus far done nothing ‘more than merely preparatory’ to committing it. (iii) Where P apprehends D in the process of committing a crime, but does not give him an opportunity to turn himself over to the police voluntarily.

Note the subtle difference between (a) a reasonable belief that D committed what is known to be an indictable offence and (b) knowledge that D committed what there are reasonable grounds for believing is an indictable offence. This subtle shift in emphasis marks the difference between lawful arrest (case (a)) and false imprisonment (case (b)).

The term ‘reasonable grounds’ also requires consideration. How might a person have reasonable grounds to believe that an offence was being committed, or has been committed? Since there are no statutes that provide a definition of ‘reasonable grounds’, we must turn to case law for assistance. In Castorina v Chief Constable of Surrey (1988), a woman was arrested in connection with a series of thefts from her former employer. She was questioned for four hours without finally being charged, after which she brought legal proceedings for false imprisonment against the Chief Constable. At trial, she won the case and was awarded damages. The trial judge held that for there to be ‘reasonable grounds’ to suspect someone of committing an offence, the facts have to be such that an ordinary person would have an ‘honest belief’ that the person had committed the offence. The Court of Appeal held that this test was too strict. To justify the arrest, there had to be evidence that would lead a ‘reasonable person’ to suspect that the arrestee had committed the offence. The test was objective: the fact that the arrestor was pathologically suspicious, or was biased towards believing that members of a certain ethnic group were naturally prone to criminal acts, would not suffice. An ‘ordinary’ person must have concrete evidence to ‘reasonably suspect’ the arrestee.

Citizen’s Arrest With A Warrant

In addition to a power of arrest without warrant for indictable offences, a private citizen may carry out a lawful arrest under the authority of an arrest warrant issued by a Magistrates’ Court. This power has always existed in certain limited circumstances. However, the Magistrates’ Courts (Civilian Enforcement Officers) Rules 2001 considerably widened the use of civilian officers to carry out arrests. The purpose of this enactment was to relieve the workload of the police by transferring responsibility for dealing with the arrest of non-violent offenders to civilian officers of the courts. Essentially, a person duly authorized by the court may arrest a person under the authority of an arrest warrant, for any offence. As with any other form of arrest, reasonable force may be used. However, private citizens do not have the power to force an entry to premises to execute an arrest warrant (the police do have this power, in some circumstances).

It is a common misconception that the person executing an arrest has to have the authorized arrest warrant with him at the time. The legislation only requires that, after having effected the arrest, the arrest warrant be shown to the arrestee ‘as soon as practicable’. An arrest performed outside the terms of the warrant, or by a person not authorized to execute it, will almost certainly be unlawful.

Citizen’s Arrest Of Persons Unlawfully ‘At Large

Section 3(1) of the Criminal Law Act 1967 provides that a person may use ‘such force as is reasonable’ to effect the lawful arrest of ‘persons unlawfully at large’. In this context, ‘persons unlawfully at large’ usually means those who have broken the terms of their bail, or who have escaped from detention.

Citizen’s Arrest Procedure

When an individual is arrested by someone other than a constable, the arrestor must either: (i) hand the arrestee over to a constable; (ii) take the arrestee to a police station; or (iii) bring the arrestee before a magistrate to answer charges. The arrestor should do one of these things within a ‘reasonable; time, although the law does not require that it be done immediately (John Lewis v Timms (1952), in which a one-hour delay was held to be acceptable).

According to section 28 of PACE, no arrest is lawful — whoever performs it — unless the arrestee is told both (i) that he is under arrest, and (ii) why he is under arrest, either at the time of arrest or very soon thereafter (generally defined as ‘as soon as practicable’). This is the case even when both the fact of arrest and the reason for it are absolutely obvious (a rule that police officers still fall foul of from time to time). Note, however, that there is no particular set of words that must be used. The only requirement, in this regard, is that the arrestor’s words be appropriate to the circumstances. Indeed, even the statement ‘You’re nicked!’ has been held to be valid. Nevertheless, it is doubtful that the courts would look kindly on a store detective who uses this form of address when apprehending a 70-year-old granny for shoplifting.


A private citizen may lawfully arrest a person when he has reasonable evidence to suspect that person of presently committing, or having committed, an indictable offence, provided that the arrest cannot practicably be performed by a police officer instead. Caution is required when arresting anyone believed to have committed an offence at an earlier time, for if it turns out that the arrestee’s actions did not amount to an offence, the arrest will have been unlawful. A private citizen may be authorized by a court to carry out an arrest under the authority of a search warrant. Anyone may lawfully arrest a person who is unlawfully ‘at large’. A person carrying out a lawful arrest may use ‘reasonable force’. If the arrest turns out to be unlawful, any force used will amount to a criminal offence and may give rise to a claim for damages.

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Definition Sources

Definitions for Citizen’s Arrest are sourced/syndicated and enhanced from:

  • A Dictionary of Economics (Oxford Quick Reference)
  • Oxford Dictionary Of Accounting
  • Oxford Dictionary Of Business & Management

This glossary post was last updated: 5th April, 2020 | 12 Views.