What is the test for establishing reasonable and probable grounds for an arrest?

The basic principle in forming reasonable and probable grounds for an arrest was classically stated by Cory J. in Storrey v. The Queen (1990), 1990 CanLII 125 (SCC), 53 C.C.C. (3d) 316 (S.C.C.) at p. 324: In summary then, the Criminal Code requires that an arresting officer must subjectively have reasonable and probable grounds on which to base an arrest. Those grounds must, in addition, be justifiable from an objective point of view. That is to say, a reasonable person placed in the position of the officer must be able to conclude that there were indeed reasonable and probable grounds for the arrest. On the other hand, the police need not demonstrate anything more than reasonable and probable grounds. Specifically they are not required to establish a prima facie case for conviction before making the arrest.

In R v. Bernshaw (1995), 1995 CanLII 150 (SCC), 95 C.C.C. (3d) 193 at paragraph 48 (S.C.C.), Sopinka J. also considered the test and observed: The existence of reasonable and probable grounds entails both an objective and a subjective component. That is, s. 254 (3) of the Code requires that the police officer subjectively have an honest belief that the subject has committed the offence and objectively, there must exist reasonable grounds for this belief.