When Is a Search Warrant Valid?
By Hans ‘John’ Kalina | Original article: February 18, 2017 | Reviewed and updated October 7, 2026
A warrant is not valid merely because police obtained a signature. The court must examine the legal authority, the facts supporting the search, its permitted scope and how it was carried out. An unlawful search does not automatically mean the evidence will be excluded.
The factual foundation for a warrant
For a conventional warrant under section 487 of the Criminal Code, information on oath must establish the required reasonable grounds connecting the things sought with a specified place and an offence. Other investigative powers have their own requirements. The supporting application is commonly called an Information to Obtain, or ITO.
The applicant must provide material information fairly, including facts that detract from the application. A challenge is not simply a fresh decision about whether the reviewing judge would have issued the warrant. The question includes whether the issuing justice could have authorized it on a legally sufficient, properly corrected record. Not every mistake invalidates a warrant. The Department of Justice’s section 8 commentary explains the governing search-and-seizure principles and authorities.
The lesson from R. v. Garabet
In R. v. Garabet, 2017 ONCA 139 (court judgment, PDF), police incorrectly attributed a text arranging a drug transaction to the accused. That attribution was central to the application to search his residence. Once it was removed, the remaining dated and imprecise information did not justify that residential search. The Court distinguished the store searches: the text supported a planned transaction at a store, not a search of the home.
The residential warrant was also overbroad, and the later vehicle warrant depended on evidence from the unlawful home search. The unnecessary dynamic entry aggravated the seriousness of the conduct; the Court did not hold that dynamic entry is inherently unlawful. Considering the combined breaches, the Court excluded the evidence, set aside the convictions and entered acquittals.
A warrant has limits
Does the application connect the evidence sought with the place to be searched?
Are significant statements accurate, complete and sufficiently current?
Does the warrant describe an appropriately justified scope rather than an unrestricted search?
Were officers searching the authorized place and looking for the authorized things?
Were the entry, force and treatment of occupants reasonable in the circumstances?
Computers and phones raise distinct privacy concerns
In R. v. Vu, 2013 SCC 60, the Supreme Court held that a place-search warrant does not automatically authorize examination of computer data. Specific prior authorization is ordinarily required. Officers encountering a device within a warranted search may be able to seize it and preserve its data, but must obtain the required authority before searching its contents. Different powers or recognized exceptions require separate analysis.
Excluding evidence is a separate question
Under section 24(2) of the Charter, the court assesses the seriousness of the state conduct, the impact on the accused’s protected interests and society’s interest in deciding the case on its merits. The outcome is fact-specific. Vu itself illustrates that a Charter breach does not invariably produce exclusion.
What should be preserved for a review?
Keep any warrant copy, seizure inventory, photographs of damage, relevant recordings and a contemporaneous account of the entry and search. Do not obstruct officers or destroy evidence. Counsel can obtain disclosure, examine the ITO and identify any necessary Charter application.
Related guidance
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