What is the test for obtaining a search warrant in a criminal matter?

In these regards it must be repeated that the context of a search warrant application is an investigatory stage procedure and not a trial or like proceeding where a judge needs to decide if guilt has been established or even if a prima facie case has been made out. That there even exists at the investigative stage of a crime competing evidentiary sign posts would not be entirely surprising, let alone fatal to the process of search warrant authorization; provided there are reasonable grounds to establish the Criminal Code’s requirements, permitting the authorizing judge to exercise his or her discretion. After all, the available process of search warrant authorization is not only to protect persons from unwarranted state intrusion on their privacy interests, but also to assist the administration of justice by permitting the obtaining of evidence to try to solve and perhaps later prosecute crime: … The state’s interest in detecting and preventing crime begins to prevail over the individual’s interest in being left alone at the point where credibly-based probability replaces suspicion. History has confirmed the appropriateness of this requirement as the threshold for subordinating the expectation of privacy to the needs of law enforcement … (Hunter v. Southam Inc. 1984 CanLII 33 (SCC), [1984] 2 S.C.R. 145 at p. 14 (Q.L.))

Sitting on review of search warrants issued by judicial officers presumed to know the law, reviewing courts “work within a narrow jurisdictional compass” (R v. Ebanks 2009 ONCA 851 at para. 20); perhaps best illustrated by this case.