Here's my take on it: They still have the ability to make fully cognitive decisions. They know completely what it is they are doing and why they are doing it. They also know the consequences of their actions.

One of the symptoms is no remorse and just general lack of caring. To me, that would also say they do not care about the laws or repercussions of breaking those laws. That being said, does that mean that it should also not matter to the rest of society or that we should in some manner overlook it or consider it to be "more understandable" given they do not care about these things? I don't think so.

To me, to put it in a very simplistic manner that would be much like excusing a young child who doesn't care when his mom says "no, don't do that!", nor does he care that it will harm the other child - but is only thinking he wants that toy, so he pushes and hits the other child til he gets the toy from the other child. Most parents wouldn't excuse this type of behavior and if you were the parents of the other child I don't know of any person that would excuse it. Why then, should we excuse even worse behavior from a grown adult based on the same symptoms, regardless of their cause? An adult understands the difference of right and wrong, a child does not - yet we would then be somehow expecting more out of our children than our adults. Would you truly see that as being rational or correct?