Robin Williams' Autopsy Found no Illegal Drugs (SAN FRANCISCO) - Authorities say an autopsy on actor Robin Williams found no alcohol or illegal drugs in his system when he committed suicide at his Northern California home in August. The Marin County sheriff's office released the autopsy results Friday. It found Williams had taken prescription medications, but in "therapeutic concentrations." The coroner ruled his death a suicide that resulted from asphyxia due to hanging. Sheriff's officials have said Williams was found in the bedroom of his home on the morning of Aug. 11.