The first trailer for director Ruben Fleischer‘s (Zombieland) crime drama Gangster Squad has gone online. The film stars Sean Penn as gangster Mickey Cohen, and centers on the Los Angeles task force (headed by Josh Brolin) assembled to bring him to justice. I’m a sucker for anything 1940s-related, but I think this trailer is pretty damn great. The cast is incredible, and Fleischer’s visual flair from his previous films looks to have matured and evolved for this more dramatic story. Above all, though, Gangster Squad looks like a lot of fun. It’s easy for period pieces like this to be drowned by solemnity (I’m looking at you, Public Enemies), but Fleischer hasn’t forgotten that there’s a lot of fun to be had in 1940s L.A. Additionally, I’m loving the different personalities on display in the ensemble. Between this, Argo, and the slew of movies slated for this fall/winter, 2012 is shaping up to be something special.