Breach of the Peace -This is used less these days. In the days before specific legislation giving the police powers of entry, search and arrest that they have now, this was a fall back power when nothing else existed.
A breach of the peace occurs when an act or threat may cause harm to a person or in his presence his property. It occurs when actions are likely to provoke such harm. A breach of the peace may occur on either public or private property.
There are police powers of entry to make that arrest of a person found committing a breach of the peace. There is also police powers of arrest of someone who the police have reasonable cause to believe is about to commit a breach of the peace. An arrest for an anticipated breach of the peace will only be lawful if the threat of the breach is imminent. There are no police powers of arrest once the breach has finished. Any arrest occurring after the breach of the peace will be unlawful. The arrested person should be released as soon as the likelihood of such breach of the peace has passed (unless arrested for an offence).
Breach of the peace police powers of entry and arrest can be used when for instance a police officer hears a domestic argument from the street, and he fears for the safety of those within the building. As with other police powers of entry, providing the entry is lawful, then the police are not liable for damage they cause.
All citizens, not just the police, are able to make an arrest to stop or prevent a breach of the peace. However, extreme caution should be taken before making such an arrest, because if the arrest is not lawful the individual making the arrest could be liable for false imprisonment.
A breach of the peace is not an offence, however if a complaint of a breach of the peace is made to the court then the Justices of the Peace Act 1361 gives courts the power to bind over offenders to keep the peace.