We generally call those people sociopaths. So there are two categories of guilt. Both are very important in our discussion and I think the emotional guilt is an existential experience that God gives us when we break His law. We have an internal awareness that we're doing something wrong. I think that this is something that every person can acknowledge as a first principle, so to speak, as true about human beings and human nature.
Humans are moral people who make moral distinctions and there is guilt that they feel.
My answer to that takes us back to the Christian view of human beings and human nature. Man is made as a moral creature. It is an ontological distinction. Part of what makes humans human is that they have a physical body and they have a soul. The soul is a substance that is capable of making moral distinctions and making moral choices.