In United States v. Busk, 693 F.2d 28 (3d Cir. 1982), the Third Circuit addressed the particularity requirement with respect to a warrant to search a multi-unit dwelling. The warrant authorized the search of 3123 Richmond Street, a property Busk was alleged to "own, occupy, or possess," for evidence of suspected illegal gambling activity. Id. at 29. That address was for a 3-story attached row house with three apartments, one on each floor. Each apartment had its own keyed lock and a separate doorbell outside the front door of the row house. The police had determined from gas and electric records that the apartment on the second floor was occupied by an associate of Busk. When police arrived to execute the warrant, they observed Busk leaving 3123 Richmond Street. They frisked him and found $16,000 and a set of keys on his person. They directed him to accompany them back to the apartment building. The police mistakenly entered 3119 Richmond Street, however, which also was a multi-unit dwelling. In that building, they searched the second and third floor apartments, but found no evidence of illegal gambling. At that point, the police realized they were in the wrong building and went to 3123 Richmond Street, where they entered the second floor apartment using Busk's keys, and seized gambling paraphernalia. The Third Circuit held that the warrant was facially defective because it identified the entire premises of a multi-unit building even though there only was probable cause to search the apartment on the second floor. The court reasoned that the police plainly understood the warrant to authorize them to search all three apartments, given that, when they mistakenly entered the building at 3119 Richmond Street, they searched the second floor and third floor apartments. On these bases, the court ruled that it was error to deny Busk's motion to suppress, and reversed his convictions and remanded for a new trial.