Empathy refers to the ability to understand and share the feelings of others.
This does not mean that con men and criminals have no feelings at all. As Meloy observed, in situations where an emotional reaction would be expected from “a more socialized, empathic individual,” they might feel little or nothing. But at the same time, they can can display “intense, unmodulated affect that is dramatized by its unpredictably.”
It is readily observed that psychopaths experience feelings such as anger, resentment, envy and jealousy. Narcissism — a core element of the sociopathic character type — can produce powerful feelings of self-righteousness and entitlement. When caught and in custody, many will feel distress — not every one of them is a cool customer.
Psychopaths certainly have the capacity to feel a range of emotions. The description of them as having reptilian (snake-like) brains is mostly a metaphor. When you consider how they are able to control, manipulate and dominate people, it is apparent that they are quite adept at understanding and sharing the feelings of others.
Lack of “empathy” or not, they are typically quite skilled at “feeling you.”