In the United States, state law varies. Some states permit citizen's arrests, but usually they may only be carried out if a person witnesses another person committing a felony or is helping police apprehend a suspect.

Other countries, such as Canada, France, and Sweden allow citizen's arrests under certain circumstances. General provisions tend to be that the crime has to be serious and the arrestee has to be caught in flagrante delicto.

In New Zealand, citizen's arrests can be made if the crime is being committed at night, is punishable by three or more years of imprisonment, and the person is attempting to escape from the person making the arrest. The person making the arrest must also inform the suspect the reason he or she is being arrested and take him or her to the nearest police officer.

Most law enforcement officials discourage anyone from performing a citizen's arrest, especially where physical force is involved. Doing so can subject a person to legal action, including charges of impersonating police, false imprisonment, kidnapping, or wrongful arrest, especially if the wrong person is apprehended or a suspect's civil rights are violated. Anyone who witnesses a crime taking place is recommended to notify the police.