Darkly Dreaming Dexter differently than a film analysis

Compare and contrast the way literary analysis would analyze Darkly Dreaming Dexter differently than a film analysis would be of the TV series. How does Dexter’s “heroic” vigilantism bleed into the real world?
You may compare or contrast the film analysis of Alfred Hitchcock’s Psycho with the medical or psychological diagnosis of Norman Bates. Is it possible to learn from the film’s fiction to allow us to see a “real world” perspective on serial killers?
How would a criminal justice perspective on Hannibal Lecter differ from a social psychological profile? How does our academic knowledge change our viewing of the film?