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House of Lords

Many statutes have conferred on constables the power to arrest without warrant where the constable suspects on reasonable grounds that a person has committed or is committing an offence. Those statutes have been interpreted in a long line of cases and the subject is dealt with in the Report of the Royal Commission on Criminal Procedure «(1982) cmd 1892). The chief issue of principle which was raised before the House of Lords in O'Hara v Chief Constable of RUC [1997] 1 All ER 129 was whether the order to arrest given to the arresting officer by his superior can in itself be sufficient to afford the constable a reasonable suspicion which will justify the arrest. Lord Steyn asserted that the decision of the House of Lords was to be come to 'on narrow grounds', since the question was whether the arrest, which was prima facie unlawful, could be justified under s 12(1) of the Prevention of Terrorism Act 1984 (the relevant provision of which was repeated in the 1989 Act). Lord Steyn's view of the argument advanced by the Chief Constable was perhaps more downright in its opposition than were the terms of the speech of Lord Hope (with which all members of the House of Lords agreed). Section 12(1) permits an arrest without warrant when the constable suspects on reasonable grounds that a person 'is or has been concerned in the commission, preparation or instigation of acts of terrorism'. The plaintiff was arrested following the briefing of a number of police officers, including the arresting officer, by a superior officer, who informed those present that the plaintiff was suspected of being involved in a terrorist murder which had recently taken place. He was arrested and questioned for two weeks, after which he was released without charge. He sued the police for, inter alia, wrongful arrest. The arresting officer swore that he had suspected that the plaintiff was involved in the murder and that he thought that, in the light of his instructions, his suspicion was reasonable. He said that he had been instructed to make the arrest as part of an operation mounted to search for weapons and to investigate the killing. He accepted that he had no basis for his suspicion other than the information received at the briefing; but no attempt was made at the trial to elicit what that information was: indeed, the briefing officer did not give evidence. The trial judge, accepting that the burden of proof was on the Chief Constable, held that, notwithstanding the fact that no details of the information in the possession of the arresting officer had been before the court, he was entitled to assume that an official briefing by a superior officer in such circumstances would have afforded those present grounds on which those at the briefing could reasonably suspect that the person to be arrested was involved in the murder which was being investigated. This was the more particularly so in view of the fact that the defence made no