Sociopaths are not usually physically violent. A typical sociopath never kills anybody and doesn't look like Charles Manson - they look like you and me and everybody else. You're not looking for someone who's recognizably evil or scary-looking, but rather someone who looks normal. Another lynchpin is dishonesty. Lying for the sake of lying. Lying just to see whether you can trick people. And sometimes telling larger lies to get larger effects.