accused assassin of U.S. President John F. Kennedy (Kennedy, John F.) in Dallas on Nov. 22, 1963. He himself was fatally shot two days later by Jack Ruby (1911–67) in the Dallas County Jail. A special President's Commission on the Assassination of President John F. Kennedy (Warren Commission), headed by Chief Justice Earl Warren, investigated from Nov. 29, 1963, to Sept. 24, 1964, and concluded that Oswald alone had fired the shots killing Kennedy and that there was no evidence that either Oswald or Ruby had been part of any conspiracy. In January 1979 a special U.S. House of Representatives Assassinations Committee, after a two-year investigation, reported that a second assassin may also have fired a shot and that there may have been a conspiracy. The evidence has remained highly debatable.

Oswald was born two months after his father's death; his mother subsequently remarried for three years, but the family moved frequently between 1939 and 1956. In October 1956 Oswald dropped out of high school and joined the U.S. Marines. A competent sharpshooter but an indifferent marine, he began expressing pro-Soviet and politically radical views and, on a hardship plea, secured release from the corps on Sept. 11, 1959. Nine days later he left for the Soviet Union, where he tried unsuccessfully to become a citizen.

In Minsk, where he was assigned to work, he met and married (April 30, 1961) Marina Nikolayevna Prusakova. Thirteen months later, in June 1962, he was able to return to the United States with his wife and three-month-old daughter, June Lee.

In January 1963 Oswald bought a .38 revolver and, in March, a rifle and telescopic sight, through the mails. On April 10 in Dallas he allegedly shot at but missed an ultrarightist, Edwin A. Walker, a former army general. Later that month he left his wife with a friend in Dallas and went to New Orleans, where he set up a one-man branch of the Fair Play for Cuba Committee and distributed pro-Castro leaflets. In September he went to Mexico City, where, according to the Warren Commission, he tried vainly to get a visa for Cuba and to get Soviet permission to return to the U.S.S.R. In October he returned to Dallas and secured a job at the Texas School Book Depository.

On the morning of November 24, while being transferred from a jail cell to an interrogation office, Oswald was shot by a Dallas nightclub owner, Jack Ruby, acting allegedly out of rage and anguish over the death of the president. Ruby was tried and found guilty of murder (March 14, 1964) and sentenced to death. In October 1966 a Texas appeals court reversed the conviction, but, before a new trial could be held, Ruby died of a blood clot, complicated by cancer (Jan. 3, 1967).