Investigators in California said today Oscar-winning actor Robin Williams’ death was a suicide by hanging: He was found dead in his bedroom, clothed, slightly suspended in a seated position with a leather belt around his neck, with one end wedged between a closet door and door frame.

At a press conference today, Lt. Keith Boyd, assistant chief deputy coroner for Marin County, Calif., said he was cold to the touch and rigor mortis had already set in.

Williams was found by his personal assistant, who broke in to his room Monday morning when he failed to respond to knocks. She was distraught in the 911 call and indicated Williams’ death was a suicide by hanging.

Williams’ wife last saw him at about 10:30 pm the night before; she left the house Monday around 10:30 am thinking he was still asleep in his room.

Neighbor Sandy Kleinman said yesterday that she saw his wife go out with the dog for a walk “in the morning.”

Boyd said some superficial cuts were found on the inside of Williams’ left wrist, and a pocket knife was found nearby. It is being tested to determine if residue on the knife is blood and if it is Williams’ blood.

“The preliminary, and I again say preliminary, result of the forensic examination reveals supporting signs that Mr Williams life ended from asphyxia due to hanging,” Boyd said.

Boyd would not say whether a suicide note was found. Nor would he discuss medications; toxicology reports won’t be available for several weeks, he said. But he did say Williams had recently sought treatment for depression.