He died committing suicide in jail-hung himself-but now he was convicted and sentenced to death and died in '67 in prison from lung cancer.
Jack Ruby dies before second trial
On January 3, 1967, Jack Ruby, the Dallas nightclub owner who killed the alleged assassin of President John F. Kennedy, dies of cancer in a Dallas hospital. The Texas Court of Appeals had recently overturned his death sentence for the murder of Lee Harvey Oswald and was scheduled to grant him a new trial.
On November 24, 1963, two days after Kennedy’s assassination, Lee Harvey 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 he was distraught over the president’s assassination. 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 also had a relationship with a number of Dallas policemen, which amounted to various favors in exchange for leniency in their monitoring of his establishments. 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 charge, maintaining that he was acting out of patriotism. In March 1964, he was found guilty and sentenced to death.
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 the findings of the Warren Commission, continue to be widely disputed.