The cast of "Gangster Squad" is starting to look pretty gangbusters.

Sean Penn, Ryan Gosling and Josh Brolin are all in negotiations for Warner Bros.' fact-based crime drama that will be directed by Ruben Fleischer ("Zombieland"), according to Deadline.com.

Penn will play the lead role of 1940s Los Angeles crook Mickey Cohen, the real life ex-boxer-turned-murderous gangster who was associated with high-rollers Meyer Lansky and Bugsy Siegel. Gosling ("Half Nelson," "Blue Valentine") and Brolin ("True Grit," "No Country For Old Men") are in talks to play two members of an elite police unit charged with tracking down and capturing Cohen.

The drama, based on a series of articles by Paul Lieberman, is being adapted by screenwriter Will Beall, a former L.A. police officer who also wrote the novel "L.A. Rex."

Dan Lin and Kevin McCormick are producing.

Meanwhile, Penn is also circling "The Last Photograph," which already has Christian Bale ("The Dark Knight Returns") on board. Gosling will soon be seen in "Crazy Stupid Love" with Emma Stone and Steve Carell, and "Drive," with Carey Mulligan. Brolin will next appear in "Men in Black III" with Will Smith and Tommy Lee Jones.

"Gangster Squad" will join a lengthy tradition of fact-based crime films made at Warner Bros. Gangster movies have long been virtually synonymous with the studio who, in the '30s and '40s, churned out classic crime fare like "The Public Enemy," "Little Caesar," "White Heat" and "The Roaring Twenties," while helping make stars out of James Cagney, Edward G. Robinson and Humphrey Bogart.