Fifty years later, we're still suspicious.
A Gallup poll released this month finds that more than 60 percent of Americans believe others besides Lee Harvey Oswald were involved in the assassination of President John F. Kennedy.
Over the years, more than 200 people and three dozen groups have been accused of being involved in Kennedy’s assassination in Dallas on Nov. 22, 1963, author Vincent Bugliosi recently told CNN. So it's understandable that conspiracy theories of all degrees of plausibility have gained — and lost — popularity in that time.
"There's a strong tradition in this country of cultures of conspiracy," said Edward Linenthal, a history professor at Indiana University. "Very often, major events for some people are never quite what they seem. Whatever it happens to be, I think behind the surface appearance, there's always some more interesting forces at work."
In the case of Kennedy's assassination, Linenthal said the magnitude of the event — the murder of the most powerful man in the world and one of the country's most popular presidents — immediately led doubters to look for alternate explanations.
"The results of what (Oswald) did were so immense … I think that's part of it, as well," said Linenthal, who also works as a consultant for the Sixth Floor Museum in Dallas. "The idea that a huge, transformative event like this couldn't have been carried out by one nobbish little man — I think that carries weight with a lot of people."
Official attempts to settle doubts about the assassination — beginning with the Warren Commission report in September 1964, which concluded that Oswald acted alone — have only fueled alternate versions of history.
Answers to many lingering questions may lie in classified CIA documents related to the assassination that are due to be released in 2017. For many, though, the circumstances of Kennedy's death will likely remain shrouded in mystery.
"It's certainly a vibrant part of American culture," Linenthal said, "and I don't think it will stop."
Here is a look at some of the more enduring conspiracy theories surrounding the assassination, according to Gallup and Wikipedia:
The Lyndon Johnson Theory
The theory: Kennedy's vice president, Lyndon Baines Johnson, is the focus of what Gallup cites as one of the most widely believed conspiracy theories pertaining to Kennedy's assassination. Johnson, it is thought, used his influence with both the FBI and the CIA to have Kennedy blackmailed, then killed.
It gained prominence because… Johnson’s involvement with the FBI, a perceived feud with the Kennedy family and a scandal involving financier Billie Sol Estes — detailed in a book by Phillip F. Nelson — were cited as motives for Johnson's role in the assassination.
Has it been debunked? No one can say for sure, given the theory's enduring plausibility in the minds of so many. An Associated Press poll taken in 2003 found that 20 percent of Americans thought Johnson had something to do with Kennedy's death. However, other competing theories - most notably that Kennedy was murdered, in part, out of revenge for the Cuban Missile Crisis - have blunted its popularity over the years.
The KGB Theory
The theory: Humiliated by the conclusion of the Cuban Missile Crisis, officials at the main security agency of the Soviet Union "programmed" one of their agents, Lee Harvey Oswald, to kill Kennedy.
It gained prominence because… Oswald's Russian wife, his extensive travel in the USSR and his purported contacts with Soviet diplomats all provide context for its legitimacy. Intriguing circumstantial evidence — including Oswald’s trip to the Russian embassy in Mexico City a few weeks before the shooting — provides ample fodder for research into this theory.
Has it been debunked? Not completely. Although the House of Representatives Select Committee on Assassinations in 1979 concluded that more than one gunman may have been involved, its findings also cleared the Soviets of any involvement. That conclusion has failed to satisfy many conspiracists, however.
The Mafia Theory
The theory: Facing deportation and seeking revenge on a president whose policies aimed to dismantle organized crime, mafia boss Carlos Marcello masterminded the assassination with help from Santo Trafficante and Johnny Roselli.
It gained prominence because... Compared to other theories, it doesn't seem so far-fetched. Members of the mafia had worked with the CIA in an attempt to assassinate Cuban president Fidel Castro, according to documents declassified in 2007. At the time, members of the mafia had the expertise to take out important people. And, compared to today's measures, security around prominent elected officials was primitively lax.
Has it been debunked? "Complicated" is a better word. With suspicions of CIA involvement — and JFK's brother Bobby, as attorney general, leading the charge against organized crime — the mafia had plenty of incentive to direct its vengeance toward others besides JFK. They had the motive and the means, but we may never know for sure if they actually pulled the trigger.
The CIA Theory
The theory: The nation's main intelligence gathering arm had a number of high-profile disagreements with the president, including one about the agency's purported involvement in plots to assassinate foreign leaders, and another over Kennedy's handling of the failed Bay of Pigs invasion. This, the theory goes, spurred several "rogue" CIA agents to mastermind the killing of JFK.
It gained prominence because... It ties many of the other conspiracy theories together — perhaps too neatly. One particular thread of the theory holds that the agency's involvement in a plot to kill Cuban leader Fidel Castro greatly displeased Kennedy and inspired fear in some quarters that Kennedy would disband the agency. But whether it was Lyndon Johnson, the mafia or Federal Reserve (another, more far-fetched theory), the CIA came to be seen as having played an important role.
Has it been debunked? Not even close. The CIA theory remains so popular, in fact, that the agency's website includes a page dedicated to discrediting its involvement in the assassination.
Fifty years later, we're still suspicious.
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