The Common Law does not require a citizen to identify oneself or carry identification of any sort. Therefore, where it may be the mark of a good citizen to identify oneself when asked to do so, a police officer must not use force to compel someone to identify oneself if he or she refuses: otherwise the officer will be guilty of criminal assault and liable to civil damages: Koechlin v. Waugh (1957), 118 C.C.C. 24. (Ont. C.A.)
Section 129(a) of the criminal code makes it an offence to willfully obstruct a public or peace officer in the execution of his or her duty. However, the Common Law has never considered it an offence of obstruction for a person to refuse to identify oneself and thus prevent a police officer from carrying out his or her general duties to investigate crimes. As was noted by Lord Parker, Chief Justice of England in Rice v. Connolly, [1966] 2 Q B. 414 (Eng. Div. Ct.) at p. 419: