Serial killers do have conscience. It isn’t that they lack conscience. It is that their consciences lack some of the capabilities that an ordinary person’s conscience. The serial killer’s conscience does exist, as is evidenced by his ability to self-regulate—and indeed to self-regulate quite as well, at least in most contexts, as the next person. But the serial killer’s conscience is not morally articulated; it lacks, at most, the ability to impose moral strictures on the serial killer’s thought and conduct. But even this it does not entirely lack, given that serial killers are, in certain respects, not entirely without morality.