Est-ce que l'odeur de cannabis (fumé / frais) peut à elle seule donner des motifs raisonnables de croire à la commission de l'infraction?

R. v. Polashek, 1999 CanLII 3714 (ON C.A.)

[13] I agree, in part, with the appellantÆs position. Had Constable Ross based his arrest of the appellant solely on the presence of the odour I would have held that there were notreasonable and probable grounds to make the arrest. Given Constable RossÆ admission that he could not from the odour alone determine whether the marijuana had been smoked recently or evenif he was detecting the smell of smoked marijuana, the presence of odour alone did not provide reasonable grounds to believe that the occupant was committing an offence. The sense of smell is highly subjective and to authorize an arrest solely on that basis puts an unreviewable discretion in the hands of the officer. By their nature, smells are transitory and thus largely incapable of objective verification. A smell will often leave no trace. AsDoherty J.A. observed in R. v. Simpson at p. 202 ôsubjectivelybased assessments can too easily mask discriminatory conductbased on such irrelevant factors as the detaineeÆs sex, colour,age, ethnic origin or sexual orientation.

[14] On the other hand, I would not go so far as was urged by the appellant that the presence of the smell of marijuana can never provide the requisite reasonable and probable grounds for an arrest. The circumstances under which the olfactory observation was made will determine the matter. It may be that some officers through experience or training can convince the trial judge thatthey possesses sufficient expertise that their opinion of present possession can be relied upon. Even in this case, the Crownadduced sufficient evidence from which the trial judge could reasonably conclude that Constable Ross accurately detected theodour of marijuana rather than some other substance.