R. v. Harflett, 2016 ONCA 248:
 As Binnie J. observed, roadside stops "sometimes develop in unpredictable ways": R. v. Nolet, 2010 SCC 24,  1 S.C.R. 851, at para. 4. In such situations the court's task is to "proceed step-by-step through the interactions of the police and the appellants from the initial stop onwards to determine whether, as the situation developed, the police stayed within their authority, having regard to the information lawfully obtained at each stage of their inquiry."
 In this case, the officer's search of the appellant's vehicle was warrantless, and was therefore presumptively unreasonable. To justify a warrantless search, the Crown must establish, on the balance of probabilities, that (i) the search was authorized by law; (ii) the law is reasonable; and (iii) the search was carried out in a reasonable manner: see R. v. Collins,  1 S.C.R. 265, at p. 278,  S.C.J. No. 15, at para. 23. The focus in this appeal is on the first and second branches of the Collins test since the appellant concedes the third branch.
 Under the first branch of the Collins test, "the state authority conducting the search must be able to point to a specific statute or common law rule that authorizes the search. If they cannot do so, the search cannot be said to be authorized by law": R. v. Caslake,  1 S.C.R. 51, at para. 12.
 Under the second branch of the Collins test, "the search must be carried out in accordance with the procedural and substantive requirements the law provides": Caslake, at para 12. The second branch is not reached unless the first is met.