Powers of arrest given to ordinary citizens under s24A of the Police and Criminal Evidence Act 1984 . An arrest can be made if someone is in the act of committing an indictable offence or where the citizen has reasonable grounds for suspecting the person to be committing an indictable offence. A private citizen can also arrest where there has been an indictable offence and there are reasonable grounds for suspecting the person to be guilty of it. In addition the arrest must be necessary to prevent the person:
• using physical injury to himself or any other person;
• suffering physical injury;
• causing loss of or damage to property;
• making off before a constable can assume responsibility for him.
If any of these conditions are not complied with, the citizen making the arrest may be sued in the law of tort for false imprisonment (see false imprisonment (trespass to person) ). See also police powers of arrest .