Sociopath or Narcissistic personality disorder

In case you haven't looked up the definitions already. 

Here they are:

Narcissistic personality disorder

Narcissistic personality disorder is a mental disorder in which people have an inflated sense of their own importance, a deep need for admiration and a lack of empathy for others. But behind this mask of ultraconfidence lies a fragile self-esteem that's vulnerable to the slightest criticism. - Mayo Clinic Staff

Sociopath

DSM-IV Definition. Antisocial personality disorder is characterized by a lack of regard for the moral or legal standards in the local culture. There is a marked inability to get along with others or abide by societal rules. Individuals with this disorder are sometimes called psychopaths.

A sociopath can be defined as a person who has Antisocial Personality Disorder. This disorder is characterized by a disregard for the feelings of others, a lack of remorse or shame, manipulative behavior, unchecked egocentricity, and the ability to lie in order to achieve one's goals.

Possible behavior and characteristics of a Sociopath

1.  Glibness and Superficial Charm.
2. Manipulative and Conning. They never recognize the rights of others and see their self-serving behaviors as permissible. They appear to be charming, yet are covertly hostile and domineering, seeing their victim as merely an instrument to be used. They may dominate and humiliate their victims.
3. Grandiose Sense of Self. Feels entitled to certain things as "their right."
4. Pathological Lying. Has no problem lying coolly and easily and it is almost impossible for them to be truthful on a consistent basis. Can create, and get caught up in, a complex belief about their own powers and abilities. Extremely convincing and even able to pass lie detector tests.
5. Lack of Remorse, Shame or Guilt. A deep seated rage, which is split off and repressed, is at their core. Does not see others around them as people, but only as targets and opportunities. Instead of friends, they have victims and accomplices who end up as victims. The end always justifies the means and they let nothing stand in their way.
6. Shallow Emotions. When they show what seems to be warmth, joy, love and compassion it is more feigned than experienced and serves an ulterior motive. Outraged by insignificant matters, yet remaining unmoved and cold by what would upset a normal person. Since they are not genuine, neither are their promises.
7. Incapacity for Love
8. Need for Stimulation. Living on the edge. Verbal outbursts and physical punishments are normal. Promiscuity and gambling are common.
9. Callousness/Lack of Empathy. Unable to empathize with the pain of their victims, having only contempt for others' feelings of distress and readily taking advantage of them.
10. Poor Behavioral Controls/Impulsive Nature
11. Rage and abuse, alternating with small expressions of love and approval produce an addictive cycle for abuser and abused, as well as creating hopelessness in the victim. Believe they are all-powerful, all-knowing, entitled to every wish, no sense of personal boundaries, no concern for their impact on others.
12. Early Behavior Problems/Juvenile Delinquency. Usually has a history of behavioral and academic difficulties, yet "gets by" by conning others. Problems in making and keeping friends; aberrant behaviors such as cruelty to people or animals, stealing, etc.
13. Irresponsibility/Unreliability. Not concerned about wrecking others' lives and dreams. Oblivious or indifferent to the devastation they cause. Does not accept blame themselves, but blames others, even for acts they obviously committed.
14. Promiscuous Sexual Behavior/Infidelity. Promiscuity, child sexual abuse, rape and sexual acting out of all sorts.
15. Lack of Realistic Life Plan/Parasitic Lifestyle. Tends to move around a lot or makes all encompassing promises for the future, poor work ethic but exploits others effectively.
16. Criminal or Entrepreneurial Versatility. Changes their image as needed to avoid prosecution. Changes life story readily.