In Balthazar v. City of Chicago, No. 12-3378 (Nov. 8, 2013), the Seventh Circuit addressed an interesting Fourth-Amendment question: is it a “search” for officers to mistakenly open the wrong apartment door and glance inside? Judge Posner said that in this case, it likely was not:
Police forced open the door of a residence by mistake, realized their mistake immediately (in fact before the door opened—for remember that Beckman tried to check the forward motion of the battering ram), and left immediately. With the door open in front of him he couldn’t have avoided seeing into the apartment without closing his eyes (which would have been dangerous). But having learned before looking that it was the wrong apartment, he wasn’t using his eyes to search for anything. Seeing can be searching, but isn’t always. Even before the door fell open, Beckman knew there was nothing to search for in the plaintiff’s apartment. . . . If you know you’re in the wrong place—a place you’re not authorized to search or want to search—the unavoidable glance through the open door is not a search.