Section 8 of the Charter protects against unreasonable searches and seizures. Among other things, for a search to be constitutionally reasonable, it must be conducted in a reasonable manner.

See R. v. Collins, 1987 CanLII 84 (SCC), at para. 23.

Point-in-time analysis

Police decisions about the manner in which a search will be carried out fall to be adjudged by what was or should reasonably have been known to them at the time the search was conducted, and not through the lens of how things turned out to be. Hindsight is not the measuring stick.

R. v. Rutledge, 2017 ONCA 635, at para. 25.

Police afforded some latitude in respect of tactical decisions regarding a warrant-supported entry

Police are entitled to some latitude on how they decide to enter premises under a warrant.

R. v. Rutledge, at para. 26.

In R. v. Rutledge, police used tear gas during the execution of a warrant, a substantial departure from the common law knock-and-announce rule, and did not disclose an intention to use tear gas in their affidavit supporting the application for a search warrant (ITO).

The Court of Appeal upheld the reasonableness of the search, recognizing that  the rights of a suspect do not exist independently of the requirements of safe and effective law enforcement.

In an assessment of the manner in which a search has been executed, a reviewing court balances the rights of suspects, on the one hand, with the requirements of safe and effective law enforcement, on the other. The trial judge did this. This is no place for the Monday morning quarterback.

R. v. Rutledge, at para. 26.