Maryland v. Garrison, 480 U.S. 79 (1987), is a United States Supreme Court case dealing with the Fourth Amendment of the United States Constitution and the extent of discretion given to police officers acting in good faith.

The Court held that where police reasonably believe their warrant was valid during a search, execution of the warrant does not violate respondent's Fourth Amendment rights.

The Baltimore Police Department were executing a warrant that said the ‘3rd floor apartment’ intending to search McWebbs apartment, when the police went upstairs they searched the 3rd floor and found drugs and cash.

The police, then discovered that the 3rd floor was actually divided into 2 apartments.

Garrison brought a 4th Amendment claim because they did not have a warrant to search his apartment, but rather they had a warrant to search McWebbs apartment, and Garrison wanted to use the 4th Amendment to suppress the drug evidence.