480 U.S. 79 (1987)
FACTS: The Baltimore City Police department obtained a warrant to search the home of Lawrence McWebb located “third floor of 2036 Park Avenue” for controlled substances and related paraphernalia. The police believed that there was only one apartment on the third floor, which in fact there were actually 2; one belonging to Garrison (defendant) and McWebb, the person listed on the warrant. Upon entering and searching the apartment, officers found drugs and other drug paraphernalia at which time; they realized that they were in the wrong apartment. Because Garrison was in violation of Maryland’s Substance Abuse Act, he was arrested.
ISSUE: Did the mistake of not having sufficient evidence or even a floor plan to assure the accuracy of going into the right apartment invalidate the warrant that would have been undeniably valid?
HOLDING: No
JUDGEMENT: Reversed
RULE OF LAW: The discovery of facts that demonstrate that a valid warrant was unnecessarily broad does not retroactively invalidate the warrant.
REASONING/RATIONALE:
The Maryland Supreme Court found that the warrant did not authorize a search of Garrison’s apartment and the police had no justification for making a warrantless entry into his premises; however that was not the case. The US Supreme Court found that the police reasonably believed that they were searching McWebb’s apartment and it was a mistake. The warrant was executed in a reasonable manner, despite the mix up. The police acted in the best of their ability and according to the information they had at the time. The search was legal.