Where was Jack Ruby at the time of JFK's assassination?

At the time of JFK's assassination on November 22, 1963, Jack Ruby was in Dallas, Texas. He owned a nightclub and was known to be active in the local social scene. Ruby claimed to have been at the Dallas Morning News building when he heard about the shooting, and he later went to the Texas School Book Depository, where he fatally shot Lee Harvey Oswald two days later.