The prosecutor must prove the defendant is guilty beyond a reasonable doubt. In order to establish a false arrest claim, the person detained must prove that the arrest is unlawful and such unlawful arrest resulted in injury.This means that the officer must be able to point to some objective facts that show you were or were about to be involved in criminal activity. If found guilty of unlawful restraint, it is a Class 4 felony. Call our firm to schedule a free initial consultation at (312) 212-1200, or fill out the form below. Physical force is often used, but it isn't required. Did police or security guards mistreat you or detain you without reasonable suspicion? Talk to Chicago false imprisonment lawyer Christopher Smith. "Felony" means an offense for which a sentence to a term of imprisonment in a penitentiary for one year or more is provided. (Source: P.A. 103-51, eff.