'21 Bridges' is a slick police action film with no real plot surprises. But, unusually for this genre, the movie shows both cops and their killers as victims of a larger system of funded crime, one which exists because the financiers are out of reach of the law. So when an intelligent and thinking man like Davis, who has worked a few things out in his own head, and from the scene of the crime he has just investigated, comes face to face with the cop killer, he is loath to kill him. He desperately engages with him, in dialogue and negotiation, as long as he can stretch it.