The case of R v Self demonstrates the danger of getting it wrong when making a citizen’s arrest. Even worse, if you use force to apprehend a wrong-doer, who is subsequently acquitted, he could sue you for assault and battery; if you arrest for a non-indictable offence, you have committed a tort; if you are mistaken about your arrestee being guilty, once again, you are liable. The Police have much broader powers of arrest under PACE 1984; furthermore, they are insured against mistakes. You are not. The moral of the story? Be absolutely certain you stand on solid ground before you act!