The narrative centers on Sergeant John O'Mara (Josh Brolin), a veteran and honest cop who is authorized by Police Chief William Parker (Nick Nolte) to form a secret squad to dismantle Cohen’s criminal empire. The squad functions as a "fellowship" of specialists, including:
: A group including a sharp-shooting cowboy and a street-smart officer, meant to represent a cross-section of mid-century archetypes. Gangster Squad
: A cynical lounge lizard who finds personal motivation only after a tragic street shooting. The narrative centers on Sergeant John O'Mara (Josh
The primary conflict is a moral and physical battle between the squad's guerrilla tactics and the sadistic savagery of Mickey Cohen (Sean Penn), who views himself as the master of his own "Manifest Destiny". Style vs. Substance Gangster Squad