One of the freshest trailers to grace the fertile servers of YouTube comes from the director of the critically and commercially successful Zombieland (2009), Ruben Fleischer. The film chronicles the story of the Los Angles Police Department fight against East Coast Mafia flooding into LA in the 40's.
As far as I can tell, the plot line involves two real-life characters from the aforementioned era. The first one is the Jewish Mickey Cohen, played by a slightly disfigured Sean Penn and the other is LAPD's chief, William H. Parker, portrayed with a commanding voice by Nick Nolte. The plot follows a gang of current and former police officers as they undertake a violent and covert operation to get to Mickey Cohen, who proudly proclaims: "When I came out here, LA was nothin'. Back East I was a gangster..out here, I am God".
The trailer seems to provide a selection of motifs and visuals borrowed from different areas of cinema. We get the noir-like look of the characters and the city itself, the femme fatale (the gorgeous Emma Stone) together with Nolte's Parker describing LA as a damsel in distress, as well as the more modern, in your face violence and slow-mo stuff, and last but not least, the Squad itself which seems to be a sort of wild west sheriff's posse, brave and self-sacrificing in their pursuit of outlaws. This might come from Fleischer's legacy as a commercials and music videos director.
Other members of the cast include Josh Brolin as John O'Mara, the one in command and Ryan Gosling as Sgt. Jerry Wooters.