Mr. Brooks, model citizen, devoted husband and father, has a secret…he’s an insatiable serial killer. He has managed to keep his two incompatible worlds apart by controlling his cunning, wicked alter ego Marshall, whom he blames for his crimes. When Brooks succumbs to one last murderous urge, an amateur photographer witnesses the killing. Suddenly Brooks finds himself entangled in the dark agenda of an opportunistic bystander, as well as hunted by an unorthodox and tenacious detective.