Arrest, in the context of law enforcement, is the act of placing a person under restraint so that they can be held for questioning about an offense or prevented from committing an offense. The use of this power is subject to constitutional protections and statutory limits, and it is often subject to the approval of a judge.
Most arrests are based on probable cause, a legal standard that requires the police to have reason to suspect that a crime has occurred or is about to be committed by the person they are taking into custody. There are many different circumstances that can give rise to probable cause, including the observation of a crime, a witness’ testimony in court, and the return of an indictment from a grand jury.
The use of the power of arrest may be governed by statutes and/or policies, which vary from state to state with some degree of consistency in peripheral areas. For example, in California, officers must provide adequate notice of their intention to arrest and have reasonable cause for believing that the suspected offenses are occurring. Those arrested must be informed of the reasons for their arrest in a timely fashion, and they are entitled to prompt judicial determinations, usually within 48 hours.
While some arrests are necessary and just, there are a large number of cases in which reasonable, less intrusive alternatives exist that would achieve the same law enforcement objectives without jeopardizing public safety or the maintenance of order. Given this, it is important that the laws of a jurisdiction reflect this reality and limit governmental intrusion into the private lives of its citizens.