Jack Ruby was born Jacob Leon Rubenstein on 25 March 1911 in the Maxwell Street area of Chicago.
His parents were often violent towards each other and regularly separated, which resulted in juvenile delinquency with time being spent in foster homes. Ruby’s mother was eventually committed to a mental hospital.
Ruby spent time at the Institute for Juvenile Research and as a young man, became part of the International Brotherhood of Teamsters. He was drafted in 1943 and served in the US Army Air Forces during World War II, working as an aircraft mechanic.
In 1947, Ruby moved to Dallas where he and his brothers shortened their surnames from Rubenstein to Ruby. He managed various nightclubs, strip clubs, and dance halls and developed close ties with many Dallas Police officers who frequented his nightclubs. He also became peripherally involved in the underworld activities of illegal gambling, narcotics, and prostitution.
At 11:21 am on 24 November 1963, while Lee Harvey Oswald (who had assassinated President John F Kennedy two days earlier in Dallas) was being escorted to jail through the basement of the Dallas police headquarters, Jack Ruby simply walked up to Oswald and shot him in the stomach, fatally wounding him.
An unconscious Oswald was taken by ambulance to Parkland Memorial Hospital (the same hospital where President Kennedy was pronounced dead two days earlier) where he died at 1:07 pm.
Ruby was instantly arrested and, minutes later, confined in a cell on the fifth floor of the Dallas police jail.
Many believe Ruby killed Oswald to keep him from revealing a larger conspiracy but Ruby denied this in his trial and pleaded innocent on the grounds that his great grief over Kennedy’s murder had caused him to shoot Oswald. The jury found him guilty of murder on 14 March 1964 and sentenced him to death.
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 cancer of the liver, brain, and lungs 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.