Albert v Lavin (Lavin v Albert)

Every citizen who witnesses an actual or reasonably apprehended breach of the peace may take reasonable steps to prevent it. In an appropriate case, those steps may include detaining the person responsible against that person’s will. At common law this is both a right and a duty, although the duty is of imperfect obligation for a citizen who is not a constable.

A person cannot justify resistance as self-defence merely by mistakenly believing that the person imposing lawful restraint is a private citizen. The restraint would remain lawful on the facts believed. An appellate court should decline to answer a certified question which does not arise on the facts and is therefore hypothetical.

An off-duty, plain-clothes constable reasonably believed that a breach of the peace was imminent when the appellant attempted to jump a bus queue. The constable restrained him and disclosed that he was a police officer. The appellant honestly but unreasonably disbelieved him and struck him several times.

The magistrates convicted the appellant under Section 51 of the Police Act 1964 of assaulting a constable in the execution of his duty. On an appeal by case stated, the Divisional Court treated a constable’s duty as the relevant exception to the general prohibition against detention without arrest. It also considered whether an unreasonable mistake could support self-defence.

The central issue before the House was resolved by the common-law right and duty of every citizen to prevent an actual or reasonably apprehended breach of the peace.

1. Appeal dismissed unanimously. Lord Diplock delivered the leading speech. Lord Simon of Glaisdale, Lord Keith of Kinkel, Lord Scarman and Lord Roskill agreed with his reasoning and disposition.
2. Per Lord Diplock, every citizen in whose presence a breach of the peace is occurring, or reasonably appears about to occur, has a right to take reasonable steps to make the person responsible refrain from breaking the peace. In an appropriate case, those reasonable steps include detention against the person’s will. The common law also imposes a duty to act, although for a citizen who is not a constable it is a duty of imperfect obligation.
3. The magistrates’ findings brought the case plainly within that common-law principle. The constable had reasonable grounds for anticipating a breach of the peace. The appellant’s later conduct amounted to a continuing breach. The restraint was therefore lawful independently of the constable’s official status.
4. It followed that the appellant’s mistake concerning the constable’s status could not make his resistance lawful. Even if the constable had been a private citizen, as the appellant believed, the citizen’s common-law authority to prevent a breach of the peace would have justified the restraint. The assault therefore fell within Section 51 of the Police Act 1964.
5. Per Lord Diplock, the House could not determine the appeal upon an erroneous assumption of law merely because both parties and the court below had proceeded upon that assumption. Once the correct common-law principle was identified, counsel for the appellant conceded that the appeal could not be pursued.
6. The Divisional Court’s certified question concerning whether an honest but unreasonable mistake could support self-defence did not arise. It was hypothetical, and the House declined to answer it.

1. House of Lords: Dismissed the appeal unanimously. The common-law authority of every citizen to prevent an actual or reasonably apprehended breach of the peace made the restraint lawful, irrespective of the constable’s official status.
2. Divisional Court: The appellant challenged his conviction by case stated. The court proceeded on the mistaken assumption that only a constable acting in the execution of duty could lawfully detain a person without arrest. It upheld the conviction and certified a question concerning honest but unreasonable belief in facts said to justify self-defence.
3. Brentford Magistrates’ Court: Convicted the appellant under Section 51 of the Police Act 1964 of assaulting a constable in the execution of his duty.