Playing a dull person of average intelligence is arguably an actor’s toughest challenge, requiring focus and subtlety, and Robert De Niro sinks this crime drama with his vacant, inattentive performance as an affectionally challenged homicide detective. Fourteen years earlier the detective abandoned his wife and son, and the son, now a homeless junkie, kills a dealer. De Niro and his partner track their suspect amid some nicely grimy New York area locations, including an abandoned casino in Long Beach (the “city by the sea”); when the partner is killed and the son becomes the sole suspect, De Niro leaves the force to save his boy from vengeful cops. This might have been the seed of a Samuel Fuller movie, but whereas Fuller would have piled on ever nuttier complications, director Michael Caton-Jones turns this into a trite family melodrama about past hurts, love, and acceptance. 108 min.