The Gangster Squad was a real-life clandestine unit of the Los Angeles Police Department which, in the late 1940s, was charged with hitting the legendary gangster Mickey Cohen where it hurt - to use guerilla tactics to disrupt and hopefully destroy the former boxer's burgeoning criminal empire.
The notorious off-the-books band was set up by controversial LAPD chief William H. Parker after legal means had failed to curtail Cohen, who was bringing east coast underworld methods and ambition to the west coast, which he saw as a land of opportunity along with millions of other Americans.
It's a fascinating story that has already partly been told by Warren Beatty in Bugsy (1991), which documented Cohen and the Jewish mafia helping Benjamin "Bugsy" Siegel get a foothold in Las Vegas, and Curtis Hanson in LA Confidential (1997), which dealt with the relationship between police corruption and Hollywood celebrity.
While Hanson's Oscar winner was inspired by a work of pulp fiction, Gangster Squad is based on a series of articles in the Los Angeles Times by Paul Lieberman and adapted for the screen by Will Beall, a former homicide detective in the famously tough area of South Central LA.
Despite those fact-based beginnings, Gangster Squad is the pulpiest, most cartoonish gangster movie since Beatty's other crime flick, Dick Tracy, with director Ruben Fleischer (Zombieland) gleefully mobilising all the tropes of the genre that go back to the days of George Raft, Edward G. Robinson and James Cagney.
The gangsters, headed by Sean Penn's Cohen, have twisted-up mugs, evil leers and a psychotic taste for blood and young flesh; the cop who heads the Gangster Squad (Josh Brolin) is a fearless straight arrow with a devoted, perky red-headed wife (Mireille Enos); the gangster's moll (Emma Stone) is slinky and wised-up; and the tommy guns are carried in violin cases.
Indeed, Penn, whose schnoz seems to be growing and tilting downward like the old Concord, and Brolin, with a jaw so square you could use it to draw up house plans, look like they were models for Mumbles and Dick Tracy in Beatty's movie.
As lurid, violent and at times hilarious pulp, Gangster Squad is entertaining enough, the kind of brisk, B-grade entertainment that Warner Bros made in the 1930s before the Production Code tempered the amount of anti-social behaviour that could be shown on screen.
Thankfully, all of the film's humour is intentional. After Brolin's John O'Mara puts together his Magnificent Seven-style team, which includes Ryan Gosling's cynical skirt chaser Jerry Wooters, the outlaw crew winds up in a Burbank jail. They use a car to remove the bars and break out but all it succeeds in doing is ripping off the bumper.
Eventually, Gangster Squad hits its straps, with the army of cops that Cohen has on his payroll unable to stop O'Mara and his crack team, which includes a sharpshooting cowboy (Robert Patrick) and a nerdy electronics expert (Giovanni Ribisi), from bringing his criminal empire to its knees through a mix of brains and brutality.
Gangster Squad was pulled after the cinema shooting in Aurora, Colorado, during a showing of The Dark Knight Rises and its climax, which originally took place in a movie theatre, reshot so that it now resembles the ending of Brian de Palma's Scarface.
While it was right for Warner Bros to hold the movie and alter the ending, Gangster Squad has little to do with reality and more to do with the tradition of the gangster movie (Fleischer cites the 1949 Cagney classic White Heat as an inspiration). Indeed, Penn's over- the-top Cohen could have been a Batman villain.
Which is what makes it fun but ultimately forgettable. While it is amusing to watch Penn chew the beautifully appointed scenery, Brolin again do a hard-boiled lawman (and way better than in the awful Men In Black 3) and Gosling and Stone play out a doomed noir-ish romance (they make it work despite the absurdity) how much better would the real story have been?
How did Cohen manage to get what seems like most of the LAPD and the judiciary in his pocket? How did an upright cop like O'Mara reconcile his old-fashioned family values with the killing spree and the law-breaking? Why didn't they just take out Cohen instead of endangering the lives of so many Angelinos?
Indeed the whole enterprise gets nuttier and more far-fetched as it races towards the crazed climax, in which half the city ends looking like Swiss cheese, leaving us to ponder what Gangster Squad might have been if it had followed the dictum of another LA cop of the same era: "Just the facts, ma'am."