John Rourke is a gritty cop pushed to the edge after an important witness is killed. He's fighting demons in his personal life that may consume him. Things come to a boil when a mysterious and deranged hitman from an unknown Chinese gang opens fire with shotguns and automatic weapons on a police conference, killing several of Rourke's closest friends.
Rourke and his partner, Roy Dickerson try to find the killer, but are strangely obstructed by their new boss, Detective McCoy. Rourke's investigation reveals corruption within his own department, and he quickly finds himself locked in an epic struggle with both a corrupt police department and an invisible criminal empire seeping it's way into the city.
Finally, as a cruel ploy to end his investigation, his son is kidnapped. Rourke tracks him down to an abandoned warehouse in the harbour, and to save the life of his son and the future of his city, Rourke must battle an entire criminal organization. When he learns that the mystery assassin is one of his closest associates in the police department, he must come to grips with the knowledge that in a world where the cops can be as corrupt as the criminals, even Paper Bullets can kill.