The fifty years since the assassination of John F. Kennedy have done little to quell the public's interest or skepticism about who killed the president.
In 1964, a year after the president's death, the President's Commission on the Assassination of President Kennedy, better known as the Warren Commission, concluded that Kennedy was killed by a single gunman, Lee Harvey Oswald, who acted alone and not part of a conspiracy.
In 1978, however, another government committee, the House of Representatives Select Committee on Assassinations, found that in addition to Oswald, there likely was a second gunman who fired at the president's motorcade. The commission concluded that the gunmen were part of a "conspiracy," without determining exactly who was behind it, opening the door to five decades and a cottage industry of theories.
According to a 2003 ABC News Poll, 70 percent of Americans believe Kennedy's death was "the result of a plot, not the act of a lone killer." Fifty-one percent believe Oswald did not act alone, and 7 percent believe Oswald was not involved at all in the assassination.
In the years since Kennedy's death more than 2,000 books have been written about the assassination, many of which espouse one or more conspiracy theories.
In no particular order and with no endorsement, here are five of the most popular Kennedy assassination conspiracy theories.
The Soviets seem like an obvious choice if you're looking for a dark hand behind Kennedy's assassination.
Proponents of the theory point to two pieces of evidence. First, the U.S. and the Soviet Union were engaged in a bitter cold war. Conspiracy theorists allege that Soviet Premier Nikita Khrushchev was so embarrassed by having to back down following the Cuban Missile Crisis he ordered the hit on Kennedy.
The other compelling piece of evidence is Lee Harvey Oswald's connection to the USSR. Though a former marine, Oswald had twice visited the Soviet Union with his Russian-born wife Marina. Both the Warren Commission and the House Committee on Assassinations found little evidence to support a Soviet-backed operation, but one former KGB agent came out years later to say the Russians played a role in the plot.
This much we know is true, the CIA had contacts with organized crime families to discuss assassinating the president. Only the president was Cuba's Fidel Castro, not Kennedy.
The mob was heavily invested in casinos and other lucrative investments in Cuba before Castro's communist revolution, according to one iteration of the theory. Kennedy botched the Bay of Pigs invasion, ending any hopes of American organized crime returning to Cuba and enraging the mafia.
Furthermore, the mob did not like Kennedy's crusading younger brother Attorney General Robert Kennedy, and hoped the younger brother would lose his influence if his brother was killed.
One version of the theory has the CIA, who had already contacted the mob about killing Castro, asking the mafia to carry out the Kennedy hit. In another version the mob is paid to kill Kennedy by anti-Castro Cubans.
Many proponents of this conspiracy theory point to Jack Ruby, the Dallas nightclub owner with known mafia connections, who killed Lee Harvey Oswald two days after his arrest.
The Warren Commission cleared the mafia from involvement in any such plot. The House Committee on Assassinations found that the mafia was not involved in a conspiracy, but did not rule out that individuals with mob ties were part of the plot.
Given that U.S. agents tried to assassinate Cuban President Fidel Castro numerous times, the theory goes, Castro decided he would repay the honor and try to assassinate Kennedy.
Perhaps the most famous proponent of the Cuban theory was President Lyndon Johnson, the man who would succeed Kennedy following the assassination.
"Kennedy was trying to get to Castro, but Castro got to him first," Johnson told ABC News in 1968.
Both the Warren Commission and the House Committee on Assassinations cleared the Cubans of any involvement and when Castro was interviewed by Bill Moyers in 1977 he called the theory "absolute insanity."
Who had the most to gain from killing Kennedy? Lyndon Johnson, the man who became president.
The gist of the theory is that Johnson was motivated by ambition and received help from members of the CIA and wealthy tycoons who believed they would profit more under a Johnson administration.
According to one version of the theory, Johnson was aided in the plot by another man who would become president, George H.W. Bush, a burgeoning CIA official who happened to be in Dallas on the day of the assassination.
In nearly every theory that involves American conspirators, be they wealthy industrialists or tough-as-nails mafiosi, one group is routinely represented – the CIA.
The Central Intelligence Agency is an easy boogeyman. Its workings and agents are a secret to most Americans, and the agency in the 1960s had a reputation for high-level political assassinations.
One theory suggests that Oswald was a CIA operative and agents tampered with his FBI file before and after the investigation to make it appear he was a communist and lone wolf.
In its 1978 report, the House Select Committee on Assassinations found that there was no indication that Oswald "had ever had contact with the Agency."
John Fitzgerald Kennedy, the 35th president of the United States, is assassinated while traveling through Dallas, Texas, in an open-top convertible.
First lady Jacqueline Kennedy rarely accompanied her husband on political outings, but she was beside him, along with Texas Governor John Connally and his wife, for a 10-mile motorcade through the streets of downtown Dallas on November 22. Sitting in a Lincoln convertible, the Kennedys and Connallys waved at the large and enthusiastic crowds gathered along the parade route. As their vehicle passed the Texas School Book Depository Building at 12:30 p.m., Lee Harvey Oswald allegedly fired three shots from the sixth floor, fatally wounding President Kennedy and seriously injuring Governor Connally. Kennedy was pronounced dead 30 minutes later at Dallas’ Parkland Hospital. He was 46.
Vice President Lyndon Johnson, who was three cars behind President Kennedy in the motorcade, was sworn in as the 36th president of the United States at 2:39 p.m. He took the presidential oath of office aboard Air Force One as it sat on the runway at Dallas Love Field airport. The swearing in was witnessed by some 30 people, including Jacqueline Kennedy, who was still wearing clothes stained with her husband’s blood. Seven minutes later, the presidential jet took off for Washington.
The next day, November 23, President Johnson issued his first proclamation, declaring November 25 to be a day of national mourning for the slain president. On that Monday, hundreds of thousands of people lined the streets of Washington to watch a horse-drawn caisson bear Kennedy’s body from the Capitol Rotunda to St. Matthew’s Catholic Cathedral for a requiem Mass. The solemn procession then continued on to Arlington National Cemetery, where leaders of 99 nations gathered for the state funeral. Kennedy was buried with full military honors on a slope below Arlington House, where an eternal flame was lit by his widow to forever mark the grave.
Lee Harvey Oswald, born in New Orleans in 1939, joined the U.S. Marines in 1956. He was discharged in 1959 and nine days later left for the Soviet Union, where he tried unsuccessfully to become a citizen. He worked in Minsk and married a Soviet woman and in 1962 was allowed to return to the United States with his wife and infant daughter. In early 1963, he bought a .38 revolver and rifle with a telescopic sight by mail order, and on April 10 in Dallas he allegedly shot at and missed former U.S. Army general Edwin Walker, a figure known for his extreme right-wing views. Later that month, Oswald went to New Orleans and founded a branch of the Fair Play for Cuba Committee, a pro-Castro organization. In September 1963, he went to Mexico City, where investigators allege that he attempted to secure a visa to travel to Cuba or return to the USSR. In October, he returned to Dallas and took a job at the Texas School Book Depository Building.
Less than an hour after Kennedy was shot, Oswald killed a policeman who questioned him on the street near his rooming house in Dallas. Thirty minutes later, Oswald was arrested in a movie theater by police responding to reports of a suspect. He was formally arraigned on November 23 for the murders of President Kennedy and Officer J.D. Tippit.
On November 24, Oswald was brought to the basement of the Dallas police headquarters on his way to a more secure county jail. A crowd of police and press with live television cameras rolling gathered to witness his departure. As Oswald came into the room, Jack Ruby emerged from the crowd and fatally wounded him with a single shot from a concealed .38 revolver. Ruby, who was immediately detained, claimed that rage at Kennedy’s murder was the motive for his action. Some called him a hero, but he was nonetheless charged with first-degree murder.
Jack Ruby, originally known as Jacob Rubenstein, operated strip joints and dance halls in Dallas and had minor connections to organized crime. He features prominently in Kennedy-assassination theories, and many believe he killed Oswald to keep him from revealing a larger conspiracy. In his trial, Ruby denied the allegation and pleaded innocent on the grounds that his great grief over Kennedy’s murder had caused him to suffer “psychomotor epilepsy” and shoot Oswald unconsciously. The jury found Ruby guilty of “murder with malice” and sentenced him to die.
In October 1966, the Texas Court of Appeals reversed the decision on the grounds of improper admission of testimony and the fact that Ruby could not have received a fair trial in Dallas at the time. In January 1967, while awaiting a new trial, to be held in Wichita Falls, Ruby died of lung cancer in a Dallas hospital.
The official Warren Commission report of 1964 concluded that neither Oswald nor Ruby were part of a larger conspiracy, either domestic or international, to assassinate President Kennedy. Despite its seemingly firm conclusions, the report failed to silence conspiracy theories surrounding the event, and in 1978 the House Select Committee on Assassinations concluded in a preliminary report that Kennedy was “probably assassinated as a result of a conspiracy” that may have involved multiple shooters and organized crime. The committee’s findings, as with those of the Warren Commission, continue to be widely disputed.