Resisting unlawful arrest is a possible justification for breaking the law. Defendants who use this defense are arguing that they should not be held liable for a crime, since the actions taken were intended to protect them from an unlawful arrest. Many courts will not tolerate any violence whatsoever (committed while resisting an unlawful arrest), and almost certainly not "deadly force", unless the police began to use violence before the defendant began to do so. In short, a defendant might be justified in running away from police attempting an unlawful arrest; but, almost certainly will not be considered justified in shooting police who attempt to do so (unless the defendant can somehow prove self-defense).