The limousine Kennedy was riding in at the time of his assassination was a 1961 Lincoln Continental four-door convertible code-named the X-100. After it was examined for evidence following the shooting in Dallas, the X-100 was overhauled, cleaned and returned to service at the White House in mid-1964. It continued to carry presidents until early 1977 and is now on display at the Henry Ford Museum in Dearborn, Michigan.

Oswald was arrested in a Texas movie theatre, less than 90 minutes after Kennedy's shooting. The film that was screening was called War Is Hell!. It was billed as being about "Iron guts guys in action who kill for medals... dames.. or just to stay alive!".

Oswald was charged with killing Kennedy and a police officer named John Tippit. On November 24, Oswald was himself shot by nightclub operator Jack Ruby while being transferred from the city jail to Dallas county jail. Oswald was taken to the same Parkland Hospital which had received Kennedy less than 48 hours earlier, but was pronounced dead a short time later. Ruby was convicted of Oswald's murder in 1964 despite a plea of insanity. Ruby developed lung cancer in prison and died in January 1967, also at Parkland Hospital.

Kennedy was the fourth US president to be assassinated. Others were Abraham Lincoln (1865), James Garfield (1881), and William McKinley (1901). America's 29th president, Warren G Harding, later revealed to have been a corrupt philanderer, was widely rumoured to have been poisoned by his wife in 1923. Coincidentally, Lincoln and Kennedy, who were elected 100 years apart, were both succeeded by vice-presidents named Johnson. Andrew Johnson became America's 17th president in 1865, and Lyndon Johnson became the 36th president in 1963.

On November 22, 1963, Oswald was working for The Texas Book Depository Company, a private firm which distributed text books to public schools in parts of Texas and Oklahoma. It is alleged he fired three shots at Kennedy with a mail-order rifle from an open window on the sixth floor of the depository. He hid the gun, bought a soft drink from a vending machine and left the building.

A 1979 US House Committee inquiry found Kennedy was "probably assassinated as a result of a conspiracy" and that there was a "high probability" a second gunman as well as Oswald fired at the president. The committee did not believe that the Soviet government, Cuban government, the FBI, the CIA or Secret Service were involved in the assassination. The committee also concluded that there was no evidence to conclude anti-Castro Cuban groups or a national syndicate of organised crime were involved, but said that did not preclude the possibility that individual members of either may have been involved.

In 1964, the report from the President's Commission on the Assassination of President Kennedy, chaired by Supreme Court Chief Justice Earl Warren (the "Warren Commission") found the shots which killed Kennedy were fired by Oswald, and that he acted alone. It also found Oswald wounded Texas governor John Connally, and killed Tippit while evading arrest. Earl Warren was a former Republican Governor of California, and the GOP's 1948 vice-presidential nominee.

The year before Kennedy was shot the US State Department lent Oswald, a former marine, $US435.71 in travel expenses to return to the United States after three years living in Russia. In 1959 Oswald sought Soviet citizenship, telling US embassy officials in Moscow "I am a Marxist". He married a Russian woman in Minsk, and the pair had a daughter in early 1962 before Oswald successfully applied to come back to America with his new family.

Alternate theories about the events of November 22, 1963 persist. The 1979 House inquiry fuelled theories of a second gunman and a wider conspiracy. Before his death in 2007, one of the Watergate burglars, former CIA Agent E. Howard Hunt, alleged Lyndon Johnson was involved in a conspiracy to kill Kennedy. Historian James Reston Jr says Oswald's intended target was Governor Connally, not President Kennedy. Perhaps most intriguingly, new analysis of the graphic home movie footage of the assassination shot by Abraham Zapruder has concluded that at one point his camera stopped, crucial frames were missing and that the first of three bullets fired by Oswald was deflected by a street sign.

Vice-president Lyndon Johnson told CBS newsman Walter Cronkite in 1969 that he did not discount the possibility Kennedy's death was the work of a foreign power: "I can't honestly say that I've ever been completely relieved of the fact that there might have been international connections," he said. Johnson requested the comment be removed from the interview for national security reasons and it only aired after his death.