The Killer Inside Me is a tight, stark anatomical study of a garden-variety sociopath’s mind. Men like Casey Affleck’s character, Lou Ford, are out there. They seem so normal, so charming, so interested in you. That’s one of the tricks they play that gets them off on their own power. Then they get you in the bedroom or slip a ring on your finger, and it’s time for the sickness to come out and play.