Lieutenant Keith Boyd made the announcement at a Tuesday press conference at the Marin County sheriff’s office in San Rafael, Calif.
Boyd said that Williams, 63, was suspended with a belt around his neck. He was clothed and rigor mortis had set in. Police said the actor was found by his assistant in a seated position in his home in Tiburon, just north of San Francisco.
An investigation is ongoing into his death, which was due to asphyxia.
A toxicology report will be conducted but will take two to six weeks to be completed.