If a person is thought to have committed an indictable offence, or any offence punishable with imprisonment, or if his address is unknown, a constable may apply to a magistrate for a warrant of arrest. Such a warrant is issued if the magistrate is satisfied that a summons might be ineffective in securing attendance in court. The warrant names or clearly describes the suspect and states the alleged offence; it may then be executed at any time by any police officer, whether or not he has the warrant in his possession. Arrest warrants are never issued to private citizens.
Police and Criminal Evidence Act 1984 s.24 (as amended)
(a) anyone who is guilty of the offence;
(b) anyone whom he has reasonable grounds for suspecting to be guilty of it.
(4) But the power of summary arrest conferred by subsection (1), (2) or (3) is exercisable only if the constable has reasonable grounds for believing that for any of the reasons mentioned in subsection (5) it is necessary to arrest the person in question.
(5) The reasons are -
(a) to enable the name of the person in question to be ascertained (in the case where the constable does not know, and cannot readily ascertain, the person's name, or has reasonable grounds for doubting whether a name given by the person as his name is his real name);
(b) correspondingly as regards the person's address;
(c) to prevent the person in question (i) causing physical injury to himself or any other person; (ii) suffering physical injury; (iii) causing loss of or damage to property; (iv) committing an offence against public decency (where members of the public going about their normal business cannot reasonably be expected to avoid the person in question); or (v) causing an unlawful obstruction of the highway;
(d) to protect a child or other vulnerable person from the person in question;
(e) to allow the prompt and effective investigation of the offence or of the conduct of the person in question;
(f) to prevent any prosecution for the offence from being hindered by the disappearance of the person in question.
Castorina v Chief Constable of Surrey  NLJ 180, CA
A company had been burgled, and the police decided it was an inside job. The managing director said she had recently dismissed P (though she did not think it was her) and that the documents taken would be useful to someone with a grudge. The police arrested P and questioned her for four hours before releasing her without charge. P sued for wrongful arrest. The Court of Appeal, reversing the Circuit judge and jury, said the arresting officers did have reasonable cause to suspect P of being responsible for this particular burglary, and that even though they could have made further enquiries, the arrest was lawful.
Hough v Chief Constable of Staffordshire (2001) Times 14/2/01, CA
A driver C was stopped because of a damaged windscreen. A note on the police national computer warned that C might be armed, so the traffic officers summoned an armed response team. C was arrested and searched, but nothing was found. The Court of Appeal dismissed C's action for false imprisonment: the arresting officers did have reasonable grounds for suspecting that C was in unlawful possession of a firearm (an arrestable offence), and that was what mattered. (Obiter, C might have an action in negligence against the officer who placed that note on the computer.)
Plange v Chief Constable of South Humberside (1992) Times 23/3/92, CA
A man P assaulted another man V, who complained to the police; P then apologised to V, and V withdrew his complaint. A police officer X arrested P and detained him for about four hours, and P sought damages for false imprisonment. Allowing P's appeal against the judge's decision to withdraw the case from the jury, and ordering a new trial, the Parker LJ said an arrest would be unlawful where the officer knew that there was no possibility of a charge being made, since he would clearly have been acting then on some irrelevant consideration or for some improper purpose.
Percy v Hall  4 All ER 523, CA
Demonstrators PP were arrested over 150 times for trespassing on military land in North Yorkshire, but the relevant byelaws made by the Secretary of State were declared invalid by the Divisional Court in Bugg v DPP. PP brought an action for wrongful arrest and false imprisonment against a number of police officers and the Attorney-General on behalf of the government. The Court of Appeal, reversing the trial judge, said the validity of the byelaws was irrelevant to this case. Simon Brown LJ said that even if the byelaws were to be regarded as void for uncertainty, entitling PP to have their convictions set aside, that would not deprive the constables of a defence of lawful justification wherever they could show they were acting in the reasonable belief that PP were committing a byelaw offence.
Police and Criminal Evidence Act 1984 s.24A (as amended)
(1) A person other than a constable may arrest without a warrant -
(a) anyone who is in the act of committing an indictable offence;
(b) anyone whom he has reasonable grounds for suspecting to be committing an indictable offence.
(2) Where an indictable offence has been committed, a person other than a constable may arrest without a warrant -
(a) anyone who is guilty of the offence;
(b) anyone whom he has reasonable grounds for suspecting to be guilty of it.
(3) But the power of summary arrest conferred by subsection (1) or (2) is exercisable only if -
(a) the person making the arrest has reasonable grounds for believing that for any of the reasons mentioned in subsection (4) it is necessary to arrest the person in question; and
(b) it appears to the person making the arrest that it is not reasonably practicable for a constable to make it instead.
(4) The reasons are to prevent the person in question -
(a) causing physical injury to himself or any other person;
(b) suffering physical injury;
(c) causing loss of or damage to property; or
(d) making off before a constable can assume responsibility for him.
R v Self  3 All ER 476, CA
D was arrested by a store detective and another member of the public on suspicion of having stolen a bar of chocolate, and assaulted them while resisting arrest. He was subsequently acquitted of the theft, but appealed against his conviction for assault. Allowing his appeal, Garland J said the citizen's power of arrest after the event is limited to situations where an arrestable offence has actually been committed by someone; since D had (by the jury's verdict) not committed such an offence the purported arrest was unlawful and he was entitled to resist.
Any citizen has a residual common law power to arrest a person who is drunk and disorderly, drunk and incapable, drunk in charge of a child or drunk in charge of a loaded gun! For practical purposes, however, the only significant common-law power of arrest still extant is the power of any citizen to arrest a person committing or imminently threatening a breach of the peace in his presence, or even to restrain such a person without actually arresting him. Breach of the peace may include passive resistance as well as actual violence, but mere loud noise is not sufficient.
Albert v Lavin  3 All ER 878, HL
A man D was charged with assaulting a constable in the execution of his duty, having resisted while an off-duty officer was restraining him from causing a disturbance in a bus queue. The Divisional Court and the House of Lords affirmed his conviction; Lord Diplock said obiter that any citizen has the power to arrest a person causing a breach of the peace, or about to do so, or even to detain him without formally arresting him.
Foulkes v Chief Constable of Merseyside  2 All ER 705, CA
A man P was locked out of his own house after a family argument, and called the police. A constable C arrived and advised P to leave the immediate area for a short time, but P refused to go and C arrested him to prevent a breach of the peace. Reversing the Assistant Recorder, the Court of Appeal said this arrest had been unlawful even though C had acted with the best of intentions. No breach had actually occurred in C's presence, and the power to arrest for an anticipated breach arises only where that anticipated breach is imminent.
Note that it is a common-law offence for any person called upon to assist a constable seeking to end a breach of the peace (by making an arrest or otherwise) to refuse or unreasonably fail to do so.
When making a lawful arrest, a constable or any other person may use such force as is reasonably necessary for the purpose (and must at least touch the person arrested to make the arrest effective) but no more. If the force used is excessive, the person arrested will have grounds for bringing a civil action or prosecution for assault; if the arrest itself is not lawful, then the person "arrested" is entitled to use reasonable force to resist and can still sue for assault and false imprisonment. The rate of damages for wrongful arrest and detention seems to be about £500 per hour for the first few hours, though an unlawful arrest does not nullify any subsequent criminal proceedings against the prisoner.
Nichols v Bulman  RTR 236, QBD
A police officer X went to A's house about 50 minutes after A had been involved in a road traffic accident, and spoke to him at the front door. Suspecting A was drunk, X asked for a specimen of breath, which A refused to give. X (outside the house) then told A (inside) that he was under arrest, and A was subsequently convicted of failing to provide a second sample after having been arrested. Quashing his conviction, Parker LJ said a lawful arrest cannot be effected by words alone, so the demand for a second sample had no legal foundation.
Police and Criminal Evidence Act 1984 s.28
(1) ... the arrest is not lawful unless the person is informed he is under arrest as soon as is practicable.
(3) ... no arrest is lawful unless the person arrested is informed of the ground for the arrest at the time of, or as soon as is practicable after, the arrest.
Subsections (2) and (4) say that where a person is arrested by a constable this information must be given even if it is obvious: the natural implication is that an ordinary citizen is not required to state the obvious, but this is not stated and there is no direct authority to support such an interpretation.
Alderson v Booth  2 All ER 271, QBD
A motorist D was taken to the police station and found to have excess alcohol in his blood, but the magistrates acquitted him because the procedures in the Road Safety Act 1967 had not been followed. Dismissing the prosecutor's appeal, the Divisional Court said there was no fixed form of words for a valid arrest, but "I must ask you to come to the police station" was not sufficient. They suggested "I arrest you" as a simple and unambiguous form. (This case pre-dates the Police and Criminal Evidence Act 1984, but is probably still good law.)
R v Fiak  EWCA Crim 2381
Two police officers found the defendant D sitting in his car, apparently drunk. When they asked him to get out of the car he did so, but then claimed he had not intended to drive and started to walk into his garden towards his house. One police officer tried to prevent him and said, "You are being detained in order for us to establish whether an offence has been committed: stay where you are." D continued trying to get into his house and there was a scuffle. D was later charged with assaulting a police officer, and the question was whether the officer had been acting lawfully. Upholding D's conviction, the Court of Appeal said that although the officer had not used the word "arrest", her words and acts had been the first stages of a valid arrest (for being in charge of a vehicle while intoxicated), the completion of which she had sensibly elected to postpone for a short time while the facts were investigated.
Under common law, a person other than a constable who arrests a suspect must hand him over to a constable without unreasonable delay; a constable must take the suspect to a police station.
John Lewis v Tims  1 All ER 1203, HL
A suspected shoplifter R was arrested and detained in the manager's office for about an hour, while the store detective (in compliance with store policy) waited for the manager to be available to authorise a prosecution. R's action for false imprisonment failed: the House of Lords said this was not unreasonable: a person arrested by an ordinary citizen must be handed over to the police as soon as reasonably practicable, but not necessarily immediately.
Police and Criminal Evidence Act 1984 s.30
(1) Where a person is arrested by a constable, or taken into custody by a constable after being arrested by another person, he shall be taken to a police station as soon as practicable.
[There are some specific exceptions to this where there are practical difficulties, or where the constable realises before reaching the police station that there are no grounds for keeping the suspect under arrest, and there may be room for very limited investigation.]
Dallison v Caffrey  2 All ER 610, CA
A man P suspected of taking money from a safe was arrested by the police. He claimed an alibi and referred to an untraceable man; the constable took him to the police he claimed he had been, where neighbours confirmed his alibi. P was charged with the offence, but in the light of the neighbour's evidence the prosecution was dropped. The Court of Appeal denied P's claim of false imprisonment; in the circumstances, it was reasonable for the constable to take P with him while checking his alibi.
Police and Criminal Evidence Act 1984 s.32
(1) A constable may search an arrested person if he has reasonable grounds for believing that the arrested person may present a danger to himself or others.
(2) A constable shall also have power to search the arrested person for anything which he might use to assist him to escape from lawful custody, or which might be evidence relating to an offence.