Is this somebody you know?
"...the most devastating features of psychopathy are a callous disregard for the rights of others and a propensity for predatory and violent behaviors. Without remorse, psychopaths charm and exploit others for their own gain. They lack empathy and a sense of responsibility, and they manipulate, lie and con others with no regard for anyone's feelings."
Read on: http://www.crimelibrary.com/criminal_mind/psychology/robert_hare/3.html
Just in case you were wondering about Dr Hare's credentials, he co-wrote DSM-IV.