Maryland v. Garrison

In Maryland v. Garrison, 94 L. Ed. 2d 72, Baltimore police obtained a search warrant for “the premises known as 2036 Park Avenue third floor apartment” and for a suspect named McWebb. Officers believed that the third floor of the building contained only one apartment. Based on that understanding, the warrant described the place to be searched as the third-floor apartment.

When officers executed the warrant, they discovered that the third floor was actually divided into two separate apartments. One was McWebb’s apartment, and the other belonged to Garrison. Before the officers realized the layout problem, they entered and searched Garrison’s apartment and found contraband. Once they became aware that the third floor contained two separate units and that they were in Garrison’s apartment rather than McWebb’s, the search of Garrison’s apartment was discontinued.

Garrison challenged the search, arguing that the warrant did not validly authorize officers to search his separate apartment. The case reached the Supreme Court of the United States after the Maryland courts found the search unconstitutional.

The plain-English question was whether police violate the Fourth Amendment when they search the wrong apartment under a warrant that was based on a reasonable but mistaken belief about the building’s layout.

More specifically, the Court had to decide whether the warrant was invalid because it described the entire third floor as one apartment when there were actually two apartments, and whether the officers’ search of Garrison’s apartment was unreasonable once that mistake became apparent.

The Supreme Court held that the search did not violate the Fourth Amendment under the circumstances. The Court ruled that the warrant was valid when it was issued because the officers’ belief that the third floor contained only one apartment was objectively reasonable based on the information available to them at the time.

The Court explained that the validity of a warrant must be judged in light of what officers knew or reasonably should have known when they applied for it, not based only on facts discovered later. A factual mistake in a warrant does not automatically make the warrant unconstitutional if the mistake was reasonable and the officers did not know, and had no reason to know, that the description was overbroad.

The Court also addressed execution of the warrant. Officers may act on a warrant based on a reasonable understanding of the place to be searched, but their authority is limited by what they know or should know during the search. Once officers realize, or reasonably should realize, that the warrant does not cover a separate area or separate residence, they must stop searching that area unless they have another lawful basis to continue.

The practical rule from Maryland v. Garrison is that reasonable factual mistakes about the place to be searched can be excused, but only up to the point where the mistake remains objectively reasonable.

Maryland v. Garrison is an important warrant case for officers because it recognizes that search warrants are often obtained and executed in real-world conditions where building layouts, apartment divisions, and occupancy details may not be obvious. The Fourth Amendment does not demand perfection. It demands reasonableness.

Before applying for a warrant, officers should make reasonable efforts to accurately identify the place to be searched. If a building may contain multiple units, officers should investigate that issue as much as practical and should describe the target location with as much particularity as the facts allow. The case does not give officers permission to ignore obvious signs of multiple apartments or to rely on careless assumptions.

During execution, officers must stay alert to facts that may narrow or change their authority. If officers discover that the warrant description is broader than the actual probable cause supports, they should stop searching any area that is not covered. In this case, the Court found the search reasonable because the officers’ misunderstanding was reasonable and the search of Garrison’s apartment ended once the mistake was discovered.

For police work, the key lesson is documentation and reassessment. Officers should be able to explain what they knew when they sought the warrant, why the description was reasonable, what they observed during execution, and when they realized any mistake. A reasonable mistake may survive constitutional review, but an unreasonable failure to investigate or a continued search after the mistake becomes clear may not.