7 Conspiracy Theories About Marilyn Monroe

In the days following Marilyn Monroe’s death in August 1962, the only question widely posited in the media was whether the overdose that killed her was accidental or intentional.

Monroe’s final years were turbulent, to say the least. In 1961, she and her third husband, playwright Arthur Miller, had divorced, and Monroe had reportedly experienced three lost pregnancies during their marriage. Her last two films—the 1960 George Cukor comedy Let’s Make Love and the 1961 John Huston Western The Misfits—hadn’t lived up to box office expectations, leading to speculation that her star power was waning. Just two months before her death, she’d been fired from the 20th Century Fox romantic comedy Something’s Got to Give over frequent absences; the studio then sued her for $500,000, claiming her behavior had cost it $2 million. Monroe had become withdrawn in her final months, spending much of her time in her modest Los Angeles home.

Still, her career was far from over. Days before her death, she signed a $1 million deal to make two more movies with the studio that had recently fired her, and she was due to resume production on Something’s Got to Give the Monday following her death. But when authorities investigated after her body was discovered in the early morning hours of August 5, they seemingly did not suspect foul play. On August 6, newspapers were reporting that Monroe had died by suicide.

The narrative began to change two years after her death, when a right-wing writer pounced on rumors that Monroe was romantically involved with both President John F. Kennedy and his brother, Attorney General Robert F. Kennedy, and spun an elaborate theory accusing the latter of having Monroe killed to silence her. Since then, a string of conspiracy theories has linked Monroe’s death to everything from a Mafia plot to a UFO coverup. Here are seven Marilyn Monroe conspiracy theories that have gained traction over the years.

If you or someone you know needs help, contact the national Suicide and Crisis Lifeline by calling or texting 988 or visiting 988lifeline.org.

Conspiracy theory #1: Robert F. Kennedy had Marilyn Monroe murdered to cover up their affair.

This is widely considered to be the first Monroe conspiracy theory. It was posited by author and publisher Frank A. Capell in his July 1964 pamphlet The Strange Death of Marilyn Monroe, which, not coincidentally, was released while Robert F. Kennedy was running for a seat in the U.S. Senate. In Capell’s version of events, Monroe was surrounded by communists and communist sympathizers, including her personal physician, Dr. Hyman Engelberg, and her third husband, Arthur Miller. Capell describes Kennedy as a “sex-depraved V.I.P.” who would “stop at nothing to attain his goal which is to be president of the United States.” He theorized that Monroe was having an affair with the married Kennedy and threatened to expose their relationship, and that Kennedy ordered Engelberg to inject her with a fatal dose of drugs to silence her.

Conspiracy theory #2: RFK had Marilyn Monroe murdered because she knew too much about the Kennedys.

The next major entry in the Marilyn Monroe conspiracy theory canon came in 1975, when crime reporter and music journalist Anthony Scaduto wrote an article titled “Who Killed Marilyn Monroe” for Oui, an adult magazine that was then owned by Hugh Hefner’s Playboy Enterprises. The theory once again lays the blame for Monroe’s death at Robert Kennedy’s feet, but Scaduto posited that she was killed not to cover up an affair, but because she kept a diary that contained damaging information about the Kennedy family.

Conspiracy theory #3: Marilyn Monroe’s death was accidental, but the true circumstances were covered up by RFK and his brother-in-law, Peter Lawford.

In 1985, Irish journalist Anthony Summers published Goddess, an exhaustively researched biography of Monroe that drew on hundreds of interviews. Summers believes Monroe died of an accidental, self-administered overdose, but he blames Robert Kennedy and his brother-in-law, actor Peter Lawford, for enabling Monroe’s unhealthy use of alcohol and drugs to the point of her fatal overdose. In his narrative, Monroe “engaged in intermittent sexual encounters” with both prominent Kennedy brothers, and perhaps even hoped one of them would divorce his wife and marry her. Summers writes that, when Robert tried to end his affair with Monroe, she “proved hard to discard,” and Lawford was probably “assigned to contain the danger.” Summers also thinks Monroe was found alive sometime during the night of August 4, possibly by Lawford and Kennedy, but that she died en route to the hospital, and Kennedy and Lawford conspired with medical personnel and public officials, including FBI Director J. Edgar Hoover, to hide the true circumstances of her death.

Summers is a widely respected historian—he would eventually be nominated for a Pulitzer Prize in History for his work on 2012’s The Eleventh Day: The Full Story of 9/11 and Osama Bin Laden—so his take perhaps carries more weight than others. Still, there’s a lot of guesswork involved, and since all of the principal players are dead, there’s no way to confirm Summers’s theory.

Conspiracy theory #4: Marilyn Monroe was accidentally killed by her doctor and housekeeper.

In his 1993 book Marilyn Monroe: A Biography, Donald Spoto claims Monroe died after her housekeeper, Eunice Murray, administered a chloral hydrate enema that lethally interacted with a prescription drug Monroe had already taken. In Spoto’s reconstruction of Monroe’s final hours, the actress’s psychiatrist, Ralph Greenson, prescribed the chloral hydrate to help Monroe sleep, not realizing—either by oversight or because no one told him—that her physician was also giving her Nembutal, a barbiturate used to treat insomnia and anxiety. Spoto writes that, when they realized Monroe was dead, “Greenson and Murray must have felt an almost paralyzing panic as the enormity of the disaster became clear to them,” and that the two staged the scene to look like a suicide.

Conspiracy theory #5: The CIA killed Marilyn Monroe to punish the Kennedys after the Bay of Pigs debacle.

There has long been speculation that the CIA was involved in Monroe’s death, but this theory got a boost in 2004 thanks to the book Marilyn’s Last Words by Matthew Smith. Smith contends that a “group of CIA renegades,” believing the Kennedy brothers had “turned their backs” on the agency’s ill-fated attempt to invade Cuba and depose Fidel Castro, murdered Monroe and staged her death to look like a suicide, hoping one or both Kennedys would be implicated or at least politically damaged.

Conspiracy theory #6: The Mafia killed Marilyn Monroe for reasons.

This theory was propped up by Sam and Chuck Giancana, the godson and brother, respectively, of Chicago Mafia boss Sam “Mooney” Giancana, in their 1993 book Double Cross. The Giancanas claim Monroe’s career was largely a product of Mafia intervention, and that Monroe was also being used by the CIA to seduce and compromise world leaders, including the president of Indonesia. The authors claim the mob boss sent four hitmen to assassinate Monroe, partly at the behest of the CIA, which wanted to silence her, and partly to hurt the Kennedy brothers. The CIA got what it wanted, but Giancana’s plans to disgrace the Kennedy family were thwarted when Monroe’s death was officially deemed a suicide.

Conspiracy theory #7: The CIA killed Marilyn Monroe because she knew too much about extraterrestrials.

The most vocal proponent of this theory seems to be Dr. Stephen Greer, an emergency-room doctor and ufologist who believes friendly aliens have been visiting our planet for decades to keep an eye on our space weapons technology. Greer claims to have obtained a classified document detailing a wiretapped telephone conversation in which Monroe threatened to go public with details about the supposed UFO crash in Roswell, New Mexico, which President Kennedy had allegedly told her all about. In a video for the New Age streaming service Gaia (above), Greer says JFK knew Monroe had been murdered and was “very unhappy about it,” but insists the president did not order her death, claiming the assassination directive would have been “beyond the presidential level of activity.”

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