The turf explored in Gangster Squad may not be entirely accurate to historical truth, but it sure looks like the world of the movie mobster: the basics are instantly recognizable if you've seen L.A. Confidential and The Untouchables. Take a post-World War II Los Angeles, plunge it in noir, drop a ruthless gangster into the mix, and let loose an extralegal squad of cops to break the mob's rule. The crime kingpin in question is Mickey Cohen (Sean Penn), and his LAPD adversaries include a detective so square his fedora appears permanently affixed to his skull (Josh Brolin) and a ladies' man (Ryan Gosling) whose dalliance with Cohen's escort (Emma Stone) might not be the best idea for a smooth relationship. Their squad includes stalwart character actors such as Anthony Mackie, Michael Peña, Giovanni Ribisi, and an especially droll Robert Patrick. With all this talent on display, the movie must surely have some bang in its Tommy gun--but alas, director Ruben Fleischer (Zombieland) has opted for a peculiarly lighthearted, bantering tone for much of the action, which sits oddly with the gun massacres and dismemberments on display. He's also got Sean Penn in full Actor mode, snorting and stamping and wearing his prosthetic nose like a badge of pride. All of which might make for a juicy piece of entertainment, if the film didn't keep tripping over its own clichés and periodically losing its momentum. (Gangster Squad was bumped from its original 2012 opening date after the mass shooting at a Colorado movie theater; a shootout scene set in a movie theater was cut and re-shot in a different location for the film's eventual January 2013 release.) --Robert Horton