A Court recently ruled that if only one occupant of a multi-tenant apartment is present and consents to a search of the premises, the search is considered legal. However, if all the occupants are on the premises and one objects to the search, then the search is illegal as to that individual.
For example, two individuals were in their home when one of them, the boyfriend, was arrested and removed from the apartment. Police then asked the girlfriend, who was still in the apartment, if she would consent to a search. She did and the search turned up a gun. Both occupants were charged. The court approved of the search and found that the police had no duty to go outside and ask the boyfriend for his consent.