Gang leader "Rocky" Thorpe may be behind bars, but the city's crime wave continues unabated. The police are shocked to discover that Thorpe has be communicating with his men via a shortwave radio in his cell. Seeing a way to end the bloodshed once and for all, John Franklin undergoes plastic surgery to become the gangster's identical twin. Pretending to be released on a technicality, the disguised detective is welcomed with open arms by Rocky's men. But his mistress is not so easily fooled, and has the real mobster sprung from prison. Now John finds himself on the run from both the Thorpe gang and the police, who can't tell the real racketeer from the imposter.

Gangs of New York is a stylish film noir from Republic Pictures with a tortured history. In 1936, the studio purchased the rights to Herbert Asbury's popular history of the New York underworld. After several screenwriters' attempts to adapt the book met with rejection from the Hays Office, Republic decided to go with an original story from Samuel Fuller, "suggested by" Asbury's work. A former crime reporter, Fuller was only two years into his scripting career. He would later become famous for directing hard-hitting films such as Pickup on South Street (1953), Shock Corridor (1963), The Naked Kiss (1964) and The Big Red One (1980). The Hays Office still heavily censored Fuller's script, toning down the gang violence and the illicit relationship between John Franklin and Rocky's mistress. The altered script was assigned to James Cruze, a prolific director of silents including The Covered Wagon (1923) and The Great Gabbo (1929). He had more recently made an impression in the talkie era with I Cover the Waterfront (1933). Popular supporting player Charles Bickford was tapped to showcase his skills in a rare (dual) leading role. The actor would later be nominated for the Academy Award for Best Supporting Actor three times, for The Song of Bernadette (1943), The Farmer's Daughter (1947) and Johnny Belinda (1948). The gorgeous Ann Dvorak shot to fame after appearing in another gangster picture, Scarface (1932), as Paul Muni's sister. Martin Scorsese attempted to film Asbury's book again over 60 years later, but his Gangs of New York (2002) would also end up being only tangentially connected.