Character devoid of empathy or guilt—acts rationally by self-interest, not madness. Hitchcock and De Palma perfected this archetype.
The construct of the psychopathic killer — not to be confused with the mad murderer — demands a completely different dramaturgical and visual strategy from the director. Here, no broken mind is at work, but a calculated machine. The character functions rationally, purposefully, without the emotional friction that normally creates conflict. This is the core problem for staging: How do you show absence? How do you visualize what is not there?
Hitchcock and De Palma solved this by showing the psychopathic killer from his own perspective — his visual priorities become the camera. In De Palma's Dressed to Kill or Body Double, the camera follows the perpetrator's eye movements with almost voyeuristic precision. The cuts are mechanical, the music sterile or surprisingly emotionally dissonant. The viewer is forced to perceive the world through the eyes of a person who is morally empty — and this creates a different kind of horror than the chaos of madness.
On set, this means: the movements of this character must be economical. No nervous twitches, no impulsive gestures. Every action serves a plan. The actor must understand that psychopathy often disguises itself as charm — social skill, even charisma, combined with absolute inner emptiness. This makes them more dangerous than the madman because they can move without arousing suspicion. The lighting should often be hard and cold, but not for atmospheric reasons — but because this character sees the world in objects, not in people.
In the editing, the psychopathic killer reveals himself through what he overlooks. A normal person would have a moment of remorse — a cutaway, a glance upwards. The psychopathic killer cuts directly to the next object, to the next task. Music is used sparingly, or it is bizarrely inappropriate — Beethoven during a murder, for example. The music doesn't know what the body is doing because the body itself doesn't know what it means. This creates discomfort at the editing level.