SANTA MONICA, Sept. 23 -- Presley Gerber checked into Resolutions Living of Santa Monica at 10 p.m. on Saturday. Eleven hours later he was dead. The Santa Monica Police Department is now treating his death as a suspected overdose and searching for the source of whatever drug was present in the room, making the rehabilitation facility itself part of an active police investigation.

The Los Angeles County Medical Examiner has not yet determined the official cause of Gerber's death, pending toxicology results. Those results can take weeks or months, and the office said the investigation remains ongoing with limited information available.

Officers responded to the facility at about 9:35 a.m. Sunday after a possible-overdose report. Gerber, 2...