The Criminal Law Act 1967, section 3(1) says:

A person may use such force as is reasonable in the circumstances in the prevention of crime, or in effecting or assisting in the lawful arrest of offenders or suspected offenders or of persons unlawfully at large.

and the Police and Criminal Evidence Act 1984, section 24A(1) says alongside other provisions:

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.

Both concern and provide powers for citizens arrest, one seems to be more broad and vague, but how is one to know which is relevant in a given incident? Do either or both of them require declarative invocation to be operative?

Guides to making citizens arrest on the internet widely indicate that it is important and necessary to explain to the individual being detained what is happening and that they are being arrested and what reason for, not only s24A PACE 1984 seems to specify this. If one doesn’t do that then does it imply that one is proceeding under s3 and not s24A powers?

1 Answer 1


A use of force to assist or make an arrest and the arrest itself are different things. An arrest is a legal status - restraint and detention, uses of force and deprivation of liberty - may well be necessary to effect it.

Section 3 Criminal Law Act 1967 does not provide a power of arrest. It says a person may use reasonable force to (among other things) effect or assist arrest.

Sections 24 and 24A provide for powers of arrest (by "constables" and "other persons" respectively).

Section 28 PACE says what information must be given on arrest.

28 Information to be given on arrest.

(1) Subject to subsection (5) below, where a person is arrested, otherwise than by being informed that he is under arrest, the arrest is not lawful unless the person arrested is informed that he is under arrest as soon as is practicable after his arrest.

(2) Where a person is arrested by a constable, subsection (1) above applies regardless of whether the fact of the arrest is obvious.

(3) Subject to subsection (5) below, 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.

(4) Where a person is arrested by a constable, subsection (3) above applies regardless of whether the ground for the arrest is obvious.

(5) Nothing in this section is to be taken to require a person to be informed— (a) that he is under arrest; or (b) of the ground for the arrest, if it was not reasonably practicable for him to be so informed by reason of his having escaped from arrest before the information could be given.

A passerby who trips an individual fleeing from uniformed police doesn't need to announce that they are doing so or have done so under any law. Should it be necessary, the passerby can rely on s3 CLA in defence of this use of force.

Anyone making an arrest must say so there and then or as soon as is reasonably practicable.

A use of force might be a deprivation of liberty. If this is not to effect or assist an arrest then it may be unlawful.

  • Good insight but still not IMV a complete answer. Does one of them take precedence over the other? Does the use of both of their powers need to explicitly declared? Dec 17, 2023 at 13:24
  • 1
    See substantial edit
    – Lag
    Dec 17, 2023 at 14:04

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .