False arrest is defined as any instance where a police officer or other individual detains and arrests a citizen without meeting the standards of the law. False imprisonment occurs when one person unlawfully restricts another's freedom of movement.The law generally requires that the guilty plea be vacated in order to bring forth state and federal challenges to the validity of an arrest:. Black's Law Dictionary defines false imprisonment as "A restraint of a person in a bounded area without justification or consent. Nassau County Man Wins False Arrest and Malicious Prosecution Lawsuit Against County. False Imprisonment written on road with police yellow tape. In that case, one individual holds another against their will or takes them into custody without consent or legal authority to do so. Top-Rated Nassau County Criminal Defense Attorneys Discuss the Differences Between Detention and Arrest. Detainment. Arrest. False arrest requires an arrest, but, false imprisonment only requires unlawful detention. The legal term for a wrongful arrest is "false arrest.