"Machine Gun" Jack McGurn (1905–February 15, 1936) was a key member of Al Capone's Chicago-based criminal organization known as the Chicago Outfit, and believed to be the principal assassin and planner of the 1929 St. Valentine's Day Massacre.As a youth, McGurn did not run in gangster circles, however when his father was assassinated by members of The White Hand Gang after being mistaken for Willie "Two Knife" Altieri, McGurn, with Frankie Yale's consent, killed the 3 hitmen responsible and avenged his fathers death. On hearing the news Al Capone asked Yale if he could take McGurn to Chicago and Yale agreed.He was the assassin that fired the Tommy Gun that killed Frankie Yale in 1928.He is most well-known for the infamous instance of violence on St. Valentine's Day in 1929, where he planned the attempted killing of the North Side gang leader Bugs Moran. The incident became known as the St. Valentine's Day Massacre. He remained free from suspicion, largely due to his "blonde alibi" - the nickname of girlfriend Louise Rolfe - who claimed they spent the whole day together.
