Jack Ruby, killer of Lee Harvey Oswald, was born Jacob Rubenstein on March 25, 1911, in Chicago, Illinois, to Polish immigrants Joseph and Fannie (Rutkowski or Rokowsky) Rubenstein. Upon his parents' separation, he was placed in a foster home. At age sixteen he dropped out of school and became part of the street life on Chicago's West Side. There he worked at various odd jobs, which at one time included delivering sealed envelopes for Al Capone at a dollar an errand, and engaged in years of street-fighting, often in response to anti-Semitic taunts. He moved to California in 1933 and for a while sold subscriptions to the Examiner in San Francisco. After returning to Chicago in 1937, he was hired by Leon Cooke to assist in organizing a union of junkyard workers. After losing control of the union to Chicago racketeers, Cooke was murdered by the union president in 1939. Ruby left a few months later, and it is unclear whether or not he was connected with the Chicago syndicate. In 1941 he worked for the Spartan Novelty Company and in late 1942 for the Globe Auto Glass Company and the Universal Sales Company. During World War II he was drafted into the United States Army Air Corps (1943) and spent the war at southern bases working as an aircraft mechanic. He received a good-conduct medal and was discharged in 1946 as a private first class. He then joined his brothers in the Earl Products Company, which manufactured and distributing punchboard gambling devices, miniature cedar chests, key chains, and small kitchen items. In 1947 the men changed their name to Ruby, and the brothers bought Jack out. He moved to Dallas and went into the nightclub business with his sister.
Over the next sixteen years he ran a series of mostly unsuccessful nightclubs, sold items ranging from liquid vitamin formulas to log cabins, and was arrested nine times, although no serious charges were filed. On November 24, 1963, Ruby, then proprietor of the Carousel Club, shot and killed Lee Harvey Oswald, the accused assassin of President John F. Kennedy (see KENNEDY ASSASSINATION), in the basement of the Dallas City Jail, during Oswald's transfer to the county jail. Millions of witnesses watched on national television. Although he was defended by Melvin Belli on the grounds that "psychomotor epilepsy" caused him to black out consciously while functioning physically, Ruby was convicted of murder with malice on March 14, 1964, and sentenced to death. In October 1966, however, the Texas Court of Criminal Appeals reversed the conviction on the grounds of improper admission of testimony and the necessity of a change of venue. The arrangements for a new trial in February, in Wichita Falls, were under way, when, on December 9, 1966, Ruby was admitted to Parkland Hospital in Dallas, apparently suffering from pneumonia. Testing quickly revealed terminal lung cancer. He died at Parkland on January 3, 1967, of a blood clot in his lungs and was buried in Chicago. He never married. He espoused no political affiliation or party preference, denied any involvement in a conspiracy, and maintained to the end that he shot Oswald on impulse from grief and outrage.