Convicted sex offenders are required to “register” themselves to protect potential victims. I think there should be a new law that also requires psychopathic individuals and malignant narcissists to register themselves for the monsters they are. Of course, identifying them all would be tricky (and maybe impossible), but we could start by requiring all suspected psychopaths and narcissists to take the Psychopathy Checklist developed by Dr. Robert Hare. The Checklist has been used with a great deal of success in identifying which criminals are psychopathic, and has been used to make sentencing decisions in murder cases.
Even if only a small portion of these characters were identified and registered, it would save a lot of people from becoming victimized.