Well, to make a long story short, Jack Ruby was Jewish!
Since Jack Ruby's mother was Jewish, and in Orthodox Judaism and Conservative Judaism, those with a Jewish mother (or those who underwent a halakhic conversion) are considered Jewish, then that makes him Jewish. His father was Jewish too.
Jack Ruby (whose full birth name was Jacob Leon Rubenstein) was born on March 25, 1911 in Chicago, Illinois, United States. Jack Ruby passed away on January 3, 1967 (aged 55).
On November 24, 1963, Ruby shot and killed Lee Harvey Oswald who, according to five government investigations, was the sniper who assassinated U.S. President John F. Kennedy on November 22, 1963.
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