Sadly, President John. F. Kennedy, who would have turned 100 today, will always be remembered not just for his life but for the circumstances of his death. Here are five JFK conspiracy theories.
1. It was the Soviet Union
The 1960s marked an intense time in the Cold War between the U.S. and USSR. Bryan Ghent, an expert in the assassination of John F. Kennedy at Winthrop University, told NBC News that some believe Oswald was replaced by a Soviet agent and sent back to the U.S. to assassinate the president. Ghent added that others say that Soviet officials wanted Kennedy dead after Nikita Khrushchev aligned with Fidel Castro following the Cuban Missile Crisis.
Some believe that Kennedy's death was at the hands of the mafia. National Geographic explored whether Kennedy's failure to overthrow Castro -- who closed many of the mob's casinos in Havana – was a motive for his assassination.
4. It was Lyndon Johnson
ABC News has summarized the theory that the vice president had the most to gain, and secretly worked with members of the CIA to pull off the assassination. Adding fuel to that fire, CNN wrote that Madeline Brown, a woman who claimed to have had an affair with Johnson, also claimed that hours before JFK's death, Johnson told her, "After tomorrow, those Kennedys will never embarrass me again. That's no threat. That's a promise."