You know the drill," says L.A. gang lord Mickey Cohen (Sean Penn) to his henchmen, and they immediately pick up actual drills and get to work on their victims. The screen gets sprayed with enough blood to relieve a drought. So if Mickey Cohen says "Hammer it out," are those henchmen going to get hammers and start bludgeoning?

It's a question worth pondering in "Gangster Squad,"an ultraviolent noir that often feels more like noir on crack. Excess is this movie's best friend, and it works. Directed by Ruben Fleischer ("Zombieland"), the story is based on a real-life episode in Los Angeles' illustrious crime history. In 1949, the city is under siege of the ruthless and all-powerful aforementioned Cohen. No one can touch him, least of all the LAPD, since many of the cops are on Cohen's payroll; he has judges and Hollywood bigwigs in his pocket too. As the Godfather of the West Coast, Mickey Cohen is looking to gobble up Chicago and move east. He seems unstoppable.

But one man stands in the way: Sgt. John O'Mara (Josh Brolin), a maverick in the police force devoting his career to taking Cohen down. Brolin has pretty much perfected the poker-faced tough dude on the right side of the law (see "Men in Black 3" for evidence), and though the role doesn't allow for much scope or versatility, it sure serves him in "Gangster Squad."