See also: 1903 in organized crime, other events of 1904, 1905 in organized crime and the list of 'years in organized crime'.
The headquarters of the On Leong Merchant Association is moved to N.Y, New York.
Johnny Torrio, under the alias J.T. McCarthy, opens a saloon on New York's James Street and Walker Street which operates as a bordello. Hiring several former James Street Gang members, of which he was a member as a teenager, as protection he becomes involved in Paul Kelly's Five Points Gang becoming a top lieutenant by the following year.
Emil Roeski, an associate of the Car Barn Bandits, is sentenced to life imprisonment.
February 2 - Monk Eastman is arrested after fleeing from a failed robbery. Without protection from Tammany Hall, he is later sentenced to ten years in Sing Sing Prison.
April 22 - Three of the co-leaders of the Car Barn Bandits (Gustave Marx, Harvey Van Dine, and Peter Neidermeier) are executed for a 1903 crime spree including robbery and murder.
November 1 - Richie Fitzpatrick is killed by "Kid Twist" Max Zwerbach during peace negotiations between the two rival factions of the Eastman Gang. Several weeks later the remaining men of Fitzpatrick's gang are killed by Zwerbach lieutenant Vach "Cyclone Louie" Lewis.
November 4 - Hip Sing Tong leader Mock Duck is wounded in a gunfight by three On Leong hatchet men near his Pell Street home during the New York Tong war.
Michael Coppola "Trigger Mike", Luciano crime family Capo
Joseph Lanza "Socks", New York Fulton Fish Market waterfront leader
James V. LaSala, New York (Brooklyn) mobster and Northern California drug trafficker
James T. Licavoli, Cleveland Mafia leader
Joseph Rosato, Lucchese crime family Capodecina, labor racketeer and drug trafficker
Ettore Zappi (aka Tony Russo), Gambino crime family Capo
Anthony Anastasio bodyguard, and New York (Brooklyn) racketeer
Frank Tieri "Funzi", Genovese crime family boss
Irving Vine - associate of Edward Vogel and Ralph Pierce
February 4 - Frankie Carbo, boxing promoter and Murder, Inc. member
April 22 - Harvey Van Dine, a co-leader of the Car Barn Bandits
April 22 - Gustave Marx, co-leader of the Car Barn Bandits
November 1 - Richie Fitzpatrick, Monk Eastman Gang member
1904 in organized crime Wikipedia (Text) CC BY-SA