"Gangster Squad" — This pulpy, violent tale of cops and mobsters in 1949 Los Angeles rides an uncomfortable line between outlandishness and outright parody, and it's difficult to tell which is director Ruben Fleischer's intention. Which is a problem. While the film wallows in period detail and has some sporadic moments of amusing banter, it's mostly flashy, empty and cacophonous, and it woefully wastes a strong cast led by Josh Brolin, Ryan Gosling and Emma Stone in barely developed, one-note roles. At its center is a performance from Sean Penn as mob king Mickey Cohen in which he doesn't just chew up the scenery, he rolls it around in his mouth like a handful of marbles, then spits it back out again and blows it to bits with a Tommy gun for good measure. With his mashed-up boxer's mug, thick Brooklyn accent and volatile bursts of anger, he's as cartoony as a Dick Tracy villain. While "Gangster Squad" certainly has its intended moments of humor, the laughs Penn's performance prompts might not have been part of the plan. Brolin stars as a police sergeant and heroic war veteran tasked with putting together a secret team to take down Cohen's empire by his rules — that is, no rules at all. R for strong violence and language. 113 minutes. One and a half stars out of four.