O’Hara v Chief Constable of the Royal Ulster Constabulary

A constable may arrest without warrant under a provision requiring suspicion on reasonable grounds only if the constable personally and genuinely suspects the person and the information then in the constable’s mind provides objectively reasonable grounds for that suspicion. The information may be hearsay, anonymous or supplied by another officer. It need not establish a prima facie case or later prove true.

The constable need not know everything available to the police. The court assesses the information actually possessed by the arresting constable, its source, context and the surrounding circumstances. A superior officer’s bare instruction to arrest supplies no reasonable ground by itself. The constable must receive sufficient information to exercise the statutory power independently. The person justifying an arrest bears the legal burden of proving its lawfulness.

Police officers searched the appellant’s home and arrested him without warrant under section 12(1)(b) of the Prevention of Terrorism (Temporary Provisions) Act 1984. The arresting constable had attended an operational briefing. He was told that the appellant had been involved in a terrorist murder and was instructed to arrest him. The appellant was later released without charge and claimed damages for wrongful arrest and other alleged torts.

McCollum J dismissed the wrongful-arrest claim, holding that the briefing gave the constable reasonable grounds for suspicion. The Court of Appeal in Northern Ireland, in an unreported judgment delivered by Kelly LJ, dismissed the appeal. The central issue before the House was whether the arresting constable personally possessed objectively reasonable grounds for suspicion and whether a superior officer’s instruction could itself satisfy that requirement.

1. Appeal dismissed unanimously. Lord Steyn and Lord Hope of Craighead delivered substantive speeches. Lord Goff of Chieveley, Lord Mustill and Lord Hoffmann agreed with both. The respondent bore the legal burden of proving that the arrest was lawful. On the sparse evidence, the trial judge was entitled to infer from the briefing, its source and the surrounding circumstances that the arresting constable had received sufficient information to possess reasonable grounds for suspicion.

2. Per Lord Hope, section 12(1) of the Prevention of Terrorism (Temporary Provisions) Act 1984 imposes a partly subjective and partly objective test. The arresting constable must genuinely suspect that the person was concerned in acts of terrorism. The grounds actually present in the constable’s mind at the time must also be such that a reasonable person, possessing that information, would regard the suspicion as reasonable. The court does not test information unknown to the arresting constable or require proof that the underlying facts were true.

3. Per Lord Steyn and Lord Hope, reasonable suspicion requires less than evidence establishing a prima facie case. It may rest on hearsay, an informer’s report, an anonymous tip or information received from another officer. Its reasonableness depends on the information’s source and context, viewed with the surrounding circumstances. Police officers may rely on one another, but the constable exercising the power must first receive enough information to form the required personal and objectively reasonable suspicion.

4. Per Lord Steyn, the statutory discretion and legal accountability belong to the arresting constable. A superior officer’s bare order to arrest cannot itself constitute reasonable grounds. McKee v Chief Constable for Northern Ireland [1984] 1 WLR 1358 concerned a differently worded provision requiring only honest suspicion and did not govern that objective issue. Lord Hope treated it as supporting the narrower proposition that the arresting officer’s state of mind alone is material.

5. Per Lord Hope, the trial judge applied the correct test. The constable had not merely received an order or a formulaic allegation. He had been briefed during a planned operation, had been told that the appellant was involved in a specified terrorist murder, and genuinely suspected that involvement. The trial judge could assess that information objectively and draw reasonable inferences from the official source and operational context. The Court of Appeal had therefore been entitled to uphold the dismissal of the wrongful-arrest claim.

1. House of Lords: The House unanimously dismissed the appeal and affirmed the dismissal of the wrongful-arrest claim.
2. Court of Appeal in Northern Ireland: On 6 May 1994 Kelly LJ, Pringle J and Higgins J dismissed the appellant’s appeal in an unreported judgment. They held that the information given at the briefing was sufficient under section 12(1)(b) of the Prevention of Terrorism (Temporary Provisions) Act 1984.
3. High Court of Justice in Northern Ireland: On 14 September 1990 McCollum J dismissed the wrongful-arrest and assault claims after trial. He ordered the return of unlawfully confiscated documents and awarded £100 compensation for their confiscation. Only the wrongful-arrest decision proceeded to this appeal.