She had suffered from mental illness and substance abuse, and had not completed a film since The Misfits, which was released on February 1, 1961; it was a box-office flop.
Monroe had spent 1961 preoccupied with her various health problems, and in April 1962 had begun filming Something's Got to Give for 20th Century Fox, but the studio fired her in early June. Fox publicly blamed Monroe for the production's problems, and in the weeks preceding her death she had attempted to repair her public image by giving several interviews to high-profile publications. She also began negotiations with Fox on being re-hired for Something's Got to Give and for starring roles in other productions.
Monroe spent the day of her death at her home in Brentwood. She was accompanied at various times by publicist Patricia Newcomb, housekeeper Eunice Murray, photographer Lawrence Schiller, and her psychiatrist Ralph Greenson. At Greenson's request, Murray stayed overnight to keep Monroe company. At approximately 3 a.m. on Sunday, August 5, Murray noticed that Monroe had locked herself in her bedroom and appeared unresponsive when she looked inside through a window. Murray alerted Greenson, who arrived, entered the room by breaking a window, and found Monroe dead. Dr. Greenson and Monroe's personal physician, Dr. Hyman Engelberg, who arrived later, did not notify the police until 35 minutes after Engelberg had pronounced the actress dead, a delay that has fueled suspicion.
Her death was officially ruled a probable suicide by the Los Angeles County coroner's office, based on information about her overdosing and being prone to mood swings and suicidal thoughts.
Despite the coroner's findings, several alternative theories suggesting murder or accidental overdose have been proposed since the mid-1960s. Many of these involve U.S. president John F. Kennedy and his brother Robert F. Kennedy, as well as union leader Jimmy Hoffa and mob boss Sam Giancana. Because of the prevalence of these theories in the media, the office of the Los Angeles County District Attorney reviewed the case in 1982 but found no evidence to support them and did not disagree with the findings of the original investigation. However, the report conceded that "factual discrepancies" and "unanswered questions" remained in the case.
