Gangster Squad (2013): Ruben Fleischer’s Violent Crime Picture, Starring Sean Penn, Josh Brolin, Ryan Gosling

One of the best male casts anchors Ruben Fleischer’s “Gangster Squad,” a stylishly sleek, ultra violent, ultimately shallow crime period piece.

Generic to a fault, “Gangster Squad” is set in 1949 in Los Angeles, but at least half a dozen scenes look and feel as if they were taken from other classic crime-gangster pictures, including Brian De Palma’s far superior 1987 “The Untouchables,” set in Chicago.

Nominally, the film’s star is Sean Penn, cast as the notoriously ruthless, Brooklyn-born mob king Mickey Cohen, but it’s the other two actors, Josh Brolin and Ryan Gosling, who are given meatier roles to play.

Initially, Cohen appears to be running the show in town, reaping the ill-gotten gains from the drugs, the guns, the prostitutes. Greed and corruption of the authorities rule the day: Cohen is able to dominate, not only with the protection of his own paid goons, but also the police and the politicians who he bribes and controls.

The only exception is a very small and secret crew of LAPD outsiders led by Sgt. John O’Mara (Josh Brolin) and Sgt. Jerry Wooters (Ryan Gosling), who join forces in battling Cohen, who’s perceived as one of the most dangerous mafia bosses of all time, though you could not tell it from Penn’s performance.

Will Beall’s formulaic script is based on the book “Gangster Squad” by Paul Lieberman, which I have not read, but assume is richer in detail and nuance than what we see on screen.

Politically, “Gangster Squad” is meant to be a story of redemption, of righting wrongs, of men taking back what’s theirs, based on their commitment to make a difference, to save the city they love.

In order to preserve the law in Los Angeles, the members of the gangster squad—a small group of LAPD cops secretly tasked to take on the city’s most nefarious crime lord, Mickey Cohen—would have to break it. Inspired by these true events, “Gangster Squad” depicts the height of Hollywood’s glamorous Golden Age, which was also a time of great turmoil in L.A.

As Cohen runs the town, with local government officials at the highest levels in his pocket, it takes a lot of guts—and ultra graphic violence–to put an end to his reign. And so, on this level, the movie is entertaining as a glossy actioner.

To their credit, Ruben Fleischer (who’s also one of the film’s executive producer) and his crew pay attention to the elegant art deco that defined the post-war era, when Los Angeles was being reborn and expanding. There was exuberance about the victory overseas in WWII, the men’s homecoming, and the beginning of economic boom.

The story’s interesting angle, which is underdeveloped, concerns how good guys had to act like bad guys in order to take down a tough and brutal mobster. The movie’s best scenes depict the officers’ strategy, their modus operandi in tackling Cohen’s inner workings, which was far from being by the book.

Take, for example, Josh Brolin’s Sgt. John O’Mara, who heads up the squad. He’s a decent, heroic man who returned from fighting heroically in World War II, only to realize that Mickey Cohen has stripped the city of any honor. However, because O’Mara and the other members s are operating covertly, they don’t worry much about issues of ethics, liability, and responsibility. The cops end up behaving almost as badly as the criminals, because it is the only way to defeat them.

Ryan Gosling is excellent as the cop who’s initially reluctant to join the lineup, demonstrating the moral dilemma of good guys, forced into a bad situation, in which the players have become ruthless. To get their job done, it’s essentially tough, if not impossible, to be on the right side of the law.

With so many good ingredients, it’s too bad the Fleisher’s direction is so impersonal and barely functional. I can only imagine what a director like the late Sideny Lumet, who has made Hollywood’s best policiers, or Curtis Hanson (“L.A. Confidential”) would have done with such juicy and pulpy material.

That said, “Gangster Squad” is fast-paced, easy to the eyes (if not ears), and superficially entertaining.