American Psycho

We can already tell from the beginning of the film that it is more than merely about murderous tendencies. From the moment he speaks, talking about violent kills and beheading people, no one seems to care. His lawyer quite literally won't believe his confession simply because he is a "casual man," which shows that what really matters in that world is one man's position in society. But between 2 men from opposing societal positions, something remains hollow; satisfaction and body, both unseen and irrelevant to others who aren't involved.