Robert De Niro is renowned for his Mafia heavies, but in "The Alto Knights," he plays two real-life mob bosses, Frank Costello and Vito Genovese.

The Alto Knights, out March 21, brings Robert DeNiro back to a mob movie—and stars the famed actor in dual roles. Written by Goodfellas screenwriter Nicholas Pileggi, The Alto Knights is inspired by the true story of the rivalry between Frank Costello and Vito Genovese—big names in organized crime in New York City in the mid-20th century—both played by DeNiro.

The legendary actor’s first attempt at a dual role is all gimmick, no substance in director Barry Levinson’s true-life gangster saga written by "Goodfellas" author Nicholas Pileggi.