Utah Unlawful Arrest--Any Crime is a criminal offense in the state of Utah that involves an arrest made without a warrant or probable cause. This type of crime can be charged as either a misdemeanor or felony, depending on the circumstances of the incident. There are two main types of Utah Unlawful Arrest--Any Crime: Unlawful Detention and Unlawful Arrest. Unlawful Detention involves the detention of a person by a law enforcement officer without a warrant or probable cause. Unlawful Arrest involves the arrest of a person by a law enforcement officer without a warrant or probable cause. In either case, the accused must be released from custody immediately upon the discovery that the arrest was made without legal authority.