“The mistaken execution of a valid search warrant on the wrong premises does not automatically violate the Fourth Amendment.” The officers get qualified immunity for getting out when they discovered it. Thomas v. Williams, 2018 U.S. App. LEXIS 2478 (5th Cir. Feb. 1, 2018) (2-1 yet unpublished):
The Thomases argue that Williams violated the Fourth Amendment by entering their home without a warrant. The mistaken execution of a valid search warrant on the wrong premises does not automatically violate the Fourth Amendment. See Graham v. Connor, 490 U.S. 386, 396 (1989); Garrison, 480 U.S. at 88. The validity of the execution “depends on whether the officers’ failure to realize the [inaccuracy] of the warrant was objectively understandable and reasonable.” Garrison, 480 U.S. at 88.
In Maryland v. Garrison, police officers executed a search warrant for a third-floor apartment only to discover after the search that the premises contained two apartments instead of one. Garrison, 480 U.S. at 80. The Supreme Court upheld the search on the basis that the officers’ mistake was reasonable in light of the information available to them at the time of the search. Id. at 88-89. The Court “recognized the need to allow some latitude for honest mistakes that are made by officers in the dangerous and difficult process of making arrests and executing search warrants.” Id. at 87.
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However, the violation of the constitutional right hinges upon the officers conducting a search even after realizing they are in the wrong location. See Simmons, 378 F.3d at 479 (reiterating that officers are “required to discontinue the search” upon realizing they are in the wrong residence). As the district court found, it is undisputed that Williams first conducted a sweep, which led him to decide to abort the search, and no such search was ever conducted. This protective sweep does not constitute a search, so Williams merely entering the Thomases’ residence does not constitute a “search.” See Maryland v. Buie, 494 U.S. 325, 335 (1990) (“[A] protective sweep, aimed at protecting the arresting officers, [is] not a full search of the premises …. “). Moreover, the record does not reflect that Williams remained in the residence to perform an unconstitutional search; he remained in the residence to explain to the Thomases what had happened and to ask questions about the suspect. It was not objectively unreasonable for Williams to conduct a protective sweep and remain in the Thomases’ home to explain the circumstances under which the officers inadvertently entered their home. Accordingly, because Williams did not perform a search after realizing he was at the wrong location, Williams did not violate any clearly established constitutional law. See Simmons, 378 F.3d at 479-80. The district court, again, properly granted Williams qualified immunity on this issue.