Arrest is a formal deprivation of freedom by police officers or other persons authorized to act under law in accordance with the powers granted to them by statute. As a safeguard against abuse of power, it is required in most democracies that an arrest be for a thoroughly justified reason (such as probable cause in the United States). A justice of the peace can also have a warrant to detain people for short periods under certain circumstances (called a “warrantless arrest”), but in most cases this is only permitted if they suspect the person of committing or having committed an indictable offence.

In most places, anyone who is arrested can sue for false imprisonment if they are not released quickly enough. For this reason, it is best for citizens to call the police if they see someone doing something illegal, even if it might be a minor offence.

The term can refer to a physical detention or the process of preparing for court, which includes logging details about the incident and questioning the suspect. It can also refer to the process of a judge deciding whether to grant bail.

Those who have been arrested must be taken without unnecessary delay to the magistrate for arraignment. They must be able to communicate with the officer who has made the arrest, and be capable of making a statement or answering questions (this is called a ‘fit and proper’ test). In addition, they must be able to understand what they are being charged with.