Based on a preliminary investigation, actor Robin Williams is believed to have died of suicide as a result of asphyxia due to hanging, investigators said during a news conference on Tuesday.

Williams’s personal assistant became concerned on Monday morning when Williams failed to respond to knocks on his bedroom door at his home in Tiburon, Calif., said Lt. Keith Boyd, the Marin County assistant chief deputy coroner. Williams’s assistant got into the room and found the actor unresponsive with a belt around his neck, suspended in a seated position above the floor, with the belt “wedged between the closed closet door and the door frame,” investigators said in a statement.

The investigation also found that Williams, 63, had several superficial cuts on the inside of his left wrist, and a pocket knife with a closed blade was located close to his body. There was “dry red material” found on the knife, but it has not been confirmed as blood; Boyd stressed several times that the investigation is ongoing. A toxicology report that would reveal any chemicals in his system is also pending and will be released in two to six weeks, he said.

Boyd also gave the timeline of Williams’s final hours: On Sunday night, Williams’s wife, Susan Schneider, went to bed at approximately 10:30 p.m. Williams was still awake, and they were the only people in the house. At an unknown time later that evening, Williams went to bed in a different room. Schneider left the house the next morning around 10:30 a.m. and assumed her husband was still asleep.

Around that time, Williams’s personal assistant, whom police did not identify, arrived at the house and grew worried when Williams didn’t answer knocks on the door; the assistant entered the room and made a “distraught” 911 call upon finding Williams. Schneider arrived back at the house once police and the fire department had already responded to the call.

The coroner division is treating the case as an active investigation, Boyd said, so he did not answer many questions in detail. He declined to discuss rumors that a note was found. And although Boyd confirmed that Williams was being treated for depression, he said he was prohibited from discussing other medical information.
A final news conference will be scheduled in several weeks once the toxicology report comes back.

On Monday, Williams’s publicist Mara Buxbaum said the comedian – who frequently, openly discussed his decades-long battle with alcohol and his time in rehabilitation programs – had recently struggled with “severe depression.” The actor briefly entered a treatment facility in Minnesota this summer, which, Buxbaum said at the time, was “an opportunity to fine-tune and focus on his continued commitment.”

The death of Williams, a beloved comedic and dramatic actor in wide-ranging roles such as “Mrs. Doubtfire” and his Oscar-winning turn in “Good Will Hunting,” prompted a flood of emotional tributes from grieving friends and fans on Monday. In a statement, President Obama called Williams “one of a kind” and said the comedian “gave his immeasurable talent freely and generously to those who needed it most.”

Williams’s wife asked that the media give the family privacy. “As he is remembered, it is our hope the focus will not be on Robin’s death, but on the countless moments of joy and laughter he gave to millions,” Schneider said in a statement. His 25-year-old daughter, Zelda Williams, tweeted a quote from the book “The Little Prince,” and added “I love you. I miss you. I’ll try to keep looking up.”

Williams leaves behind four completed films that demonstrate his comfort working across genres, feeding Hollywood’s appetite for mass-appeal entertainment while also taking roles in more selective, intimate dramas.

Two of the movies are set for release ahead of the Thanksgiving and Christmas holidays. Williams will star in the family comedy “Merry Friggin’ Christmas,” set for release in November. He will again play Teddy Roosevelt in “Night at the Museum: Secret of the Tomb,” the third in the franchise, primed for a Dec. 19 release.

Next year, audiences can take in one last example of his other great talent. Williams, who did extensive work voicing animated characters, will voice Dennis the Dog in “Absolutely Anything,” a mixed live-action/CGI British comedy that includes the voices of the “Monty Python” troupe.

Finally, Williams stars with Bob Odenkirk (of “Breaking Bad”) in the intimate drama “Boulevard,” which debuted at the Tribeca Film Festival in April but has yet to secure distribution.
Williams hinted last year that acting in such small films may have led to money troubles. “The movies are good, but a lot of times they don’t even have distribution. There are bills to pay,” he said in an interview with parade magazine.

He decided to return to television after 31 years – playing an ad exec in the CBS series “The Crazy Ones” – because, he told Parade, “the idea of having a steady job is appealing.”
The series, launched last September, lasted one 22-episode season. It reportedly averaged 8 million viewers, but CBS wanted higher numbers.