////I believe that once someone becomes a sociopath, they don't change.////

You're right. If you're born without a conscience or have it squashed out of you via severe childhood abuse, you can't acquire one later on. You either have one or you don't.

Most sociopaths are not dangerous and will never hurt anyone--they simply have no feelings of love or affection for anyone other than themselves. They're a pain in the ass but little else.

What criminal sociopaths do is learn to mimic real people as they get older. For example, a couple loses their son who was fighting overseas. The sociopath will see others offering their condolences to the bereaved couple. As he gets older, the socipath realizes that he must do the same so that his deficiency is not apparent.

If a coworker is hurt in a car wreck, the sociopath will express great concern for this person's well being not because he is concerned--he has no cpacity for it--but because he knows that this is what is expected of him as an adult. It's purely a survival mechanism--a way of not being caught, of not standing out in a bad way. One of the best examples I can give is Dennis Rader, the BTK killer.