When someone is deprived of liberty by someone who claims to have legal authority but is actually acting without such authority, it is considered an unlawful arrest. Also known as false arrest, unlawful arrest can be committed by law enforcement officers or civilians. The person who was wrongfully deprived of liberty in the unlawful arrest can sue for damages in a civil suit. Unlawful arrest can proceed to unlawful detainment, in which someone is held illegally in addition to being arrested.
Law enforcement officers have broad powers when it comes to making arrests. They are charged with keeping members of the public safe and arrests are among the tools which they can use. However, even law enforcement must be able to show probable cause when they make arrests. If there is a warrant for a person's arrest or a person is clearly linked with a crime, the arrest will be lawful. In cases where a law enforcement officer makes a random arrest, that arrest would be unlawful.
Civilians can, under certain situations, make what is known as a citizen's arrest. Such arrests involve situations where someone has demonstrably committed a crime and is attempting to flee the scene. A civilian can take action to detain the person until a law enforcement officer arrives. When the situation does not meet the standard necessary for a citizen's arrest, an arrest becomes unlawful.
Also known as false arrest, unlawful arrest is a civil wrong or tort. An example of a situation that might be considered a false arrest could be a case in which someone is browsing in a department store and is arrested by a private security officer on the grounds that he or she might be a shoplifter. People cannot be arrested on the grounds that they might shoplift; security officers can detain people who try to leave with merchandise they have not paid for, but they cannot make preemptive arrests.
Under the law, people are entitled to resist unlawful arrest. If the person making an arrest fails to provide identification or explain what he or she is doing, the citizen can resist. People cannot use inappropriate force to resist unlawful arrest.
Police officers are meticulously trained so that they understand the standards for making a lawful arrest. Civilians who may find themselves in situations where they need to make arrests, such as people who work as security guards, are also given careful training to reduce the risk that they will make unlawful arrests.
