Warner Bros. is making one last promotional push for Gangster Squad, before it opens in theaters nationwide January 11. The studio has debuted a three-minute extended trailer for director Ruben Fleischer's pulse-pounding crime drama that takes us back to 1940s Los Angeles. We get a much more detailed look at Sean Penn's Mickey Cohen, along with the elite L.A.P.D. squad tasked with bringing him down. Take a look at the latest footage before heading to your local theater this weekend.