Sean Penn is playing Cohen. Ryan Gosling is playing Sgt. Jerry Wooters.  Josh Brolin and Michael Pena also star. The movie is about Cohen, the Brooklyn-born gangster who was sent to Los Angeles by Meyer Lansky to keep an eye on Bugsy Siegel.

Cohen became a mob kingpin himself in the 1940s, and at one point fired rounds from two .45-caliber handguns into the ceiling of the Hotel Roosevelt lobby. "Gangster Squad" is based on a series of articles by Paul Lieberman. "L.A. Rex" author Will Beall wrote the script. Ruben Fleischer is directing and Dan Lin and Kevin McCormick are producing.