The case was "Arizona v. Hicks".
The incident was in 1984 when police entered Hicks' apartment after a shooting
injuring someone on another floor, during the search a policeman moved and
recorded the serial number of stereo equipment later found was obtained in an
armed robbery. The state trial court granted Hicks' motion to suppress the stereo
equipment based on the motion that initial search was lawful
but moving the stereo was not related to the shooting incident hence violated
Fourth amendment. The Arizona Supreme Court rejected the State's
request to review, but the U.S. Supreme Court agreed to do so.
