This guide is maintained as a current resource for September 2026 and covers only the laws of England and Wales. Information is for general guidance, not legal advice. Consult a qualified solicitor for advice specific to your situation.
Explore what legal powers the police have to arrest someone without a warrant in England and Wales. This guide explains the statutory framework under the Police and Criminal Evidence Act 1984, the necessity test, common law powers such as breach of the peace, rights during arrest, and practical examples in clear, accessible terms. Accurate guidance for public, students and professionals.
In England and Wales, police officers have specific legal powers to arrest a person without first obtaining a warrant from a magistrates' court or judge. These powers are rooted in statute and common law and are designed to balance the authority of the state to investigate and prevent crime with the fundamental right to liberty under Article 5 of the European Convention on Human Rights, as implemented through the Human Rights Act 1998. Arrest without a warrant is a significant interference with a person's freedom, so the law sets out clear grounds and necessity criteria that officers must meet before exercising this power. This article explains those legal frameworks, how the powers operate in practice, and what rights apply when an arrest takes place.
Overview: Arrest With vs Without a Warrant
A warrant of arrest is a court order issued by a magistrate or judge authorising the police to arrest a named person. This is often used in situations where a suspect is not readily accessible or when a court wants to ensure a person appears before it. In contrast, arrest without warrant gives police immediate authority to detain someone based on observed behaviour, reasonable suspicion, or threats to public safety. In most everyday policing, arrests are made without warrants under statutory powers rather than by prior judicial authorisation.
Statutory Power of Arrest: Section 24 PACE
The principal statutory power for police to arrest without a warrant in criminal matters is found in Section 24 of the Police and Criminal Evidence Act 1984 (PACE). This section, as amended, provides a consolidated framework for arrest powers applicable to all offences.
When a Constable May Arrest Without a Warrant
Under Section 24(1)–(3), a constable (a police officer) may arrest without a warrant if any of the following positions apply:
- About to Commit an Offence – the officer has reasonable grounds to believe a person is about to commit a criminal offence.
- In the Act of Committing an Offence – the officer reasonably suspects the person is currently committing an offence.
- Reasonable Grounds of Suspicion – the officer reasonably suspects a person is committing or is about to commit an offence.
- After an Offence Has Occurred – if an offence has been committed, the officer may arrest anyone they reasonably suspect to be guilty of that offence.
These criteria essentially give officers the authority to act proactively and reactively based on real‑time information and reasonable suspicion rather than waiting for a warrant to be issued.
The Necessity Test
Crucially, even if the officer has reasonable grounds under Section 24, the arrest must also be necessary. PACE Code G sets out the “necessity” criteria, which officers must reasonably believe apply before an arrest can lawfully proceed. These include:
- to ascertain the person's name or address when these are unknown or disputed;
- to prevent the person causing physical injury to themselves or others;
- to protect a child or vulnerable person;
- to prevent loss or damage to property;
- to allow the prompt and effective investigation of the offence (such as securing attendance at a police station for interview).
The necessity requirement is emphasised because without necessity, arrest would be an unjustified interference with liberty.
Other Powers of Arrest Without Warrant
While Section 24 PACE covers most standard criminal arrests, there are additional statutory powers that allow arrest without a warrant in specific contexts:
Failure to Comply with Bail or Court Orders
- Under Section 46A PACE, a person who fails to answer police bail or suspected of breaching bail conditions may be arrested without a warrant.
- The Bail Act 1976 allows arrest of someone suspected of breaching adult bail conditions to bring them before a court.
- Other statutes permit arrest for matters like failing to attend court hearings, breaching court injunctions, or contravening specific statutory orders.
These powers often arise outside classic criminal offences but still remove liberty to ensure compliance with legal obligations.
Arrest by Persons Other Than Police Officers
Under Section 24A PACE, a member of the public may make a citizen's arrest without a warrant, but only in limited circumstances:
- if someone is in the act of committing an indictable offence or is reasonably suspected of doing so;
- if an indictable offence has been committed and the individual is guilty of or reasonably suspected of it.
This power is conditional on necessity (such as preventing injury or damage) and on it not being reasonably practicable for a constable to make the arrest instead.
Common Law Arrest: Breach of the Peace
Police also have a common law power to arrest without a warrant when necessary to prevent or stop a breach of the peace. A breach of the peace may occur where harm is being done to a person or property, or where a person is in immediate danger of such harm. Officers may intervene without statutory power if immediate action is required to maintain public order.
Rights and Safeguards During Arrest
Information and Transparency
When a person is arrested, officers must:
- promptly inform them that they are under arrest; and
- explain the grounds for the arrest in clear terms.
This communication should occur “as soon as is reasonably practicable” after detainment begins. Failure to provide this information may render the arrest unlawful.
Reasonable Use of Force
Under Section 117 PACE, police may use reasonable force to effect an arrest if necessary. The level of force must be proportionate to the situation and justified by the circumstances.
Right to Release or Street Bail
If, after arrest but before arrival at a police station, officers determine the arrest is no longer necessary, the person should be released or offered street bail (released with a requirement to attend the police station at a later time).
Examples of Arrest Without Warrant in Practice
- Suspected Ongoing Burglary: An officer sees someone smashing a window and entering a house. The officer has reasonable grounds to believe a burglary is in progress and that arrest is necessary to prevent further harm.
- Unknown Identity at Scene: A person is causing violent disorder and refuses to provide a name or address. The officer reasonably believes arrest is necessary to ascertain identity.
- Failure to Comply with Bail: Someone fails to attend a scheduled court date. Police may arrest them without a warrant to bring them before the court.
- Citizen's Intervention: A member of the public sees a violent assault in progress and reasonably suspects an indictable offence. They may detain the suspect until police arrive, provided it is necessary and safe to do so.
Summary
In England and Wales, police officers can arrest without a warrant under a range of statutory and common law powers. The core statutory authority is Section 24 of the Police and Criminal Evidence Act 1984, which allows arrest where there are reasonable grounds to suspect involvement in an offence and where the arrest is necessary for legitimate purposes. Additional statutory powers cover breaches of bail or court orders, while common law supports intervention to prevent breaches of the peace. In all cases, officers must act lawfully, with reasonable grounds, and explain the arrest to the person detained. Unlawful arrest may give rise to legal challenges and remedies.
