The building at 320 Mott St. is seen in New York, Wednesday, Feb. 5, 2014. Four people are in custody on drug charges after police executed search warrants at three apartments in the building. (AP Photo/Seth Wenig)NEW YORK (AP) — Four individuals had been taken into custody on drug expenses after police investigating Philip Seymour Hoffman's dying achieved search warrants, two individuals with data of the investigation said Wednesday, and the clinical examiner's administrative center said extra checks are needed to decide what killed him.