John Wayne Gacy Jr.

Curiously, Morrison separates serial killers from psychopaths, because to her psychopaths are human (mean ones) and serial killers are not — or, not quite.

Dr. Robert Hare

Yet her descriptions of the traits and behaviors of serial killers closely match many of the traits and behaviors on Robert Hare's "Psychopathy Checklist-Revised." While she says serial killers are not as organized in their methods as psychopaths, no one has said that psychopaths are inherently organized. It's also true that there certainly are serial killers who have planned and prepared for their crimes. She then points out that the structure of a psychopath's personality fits with a Freudian scheme of id, ego, and superego, while a serial murderer's does not, because his personality is "all bits and pieces." If one does not accept psychoanalytic theories, this may be an irrelevant distinction.

Back to psychopaths: What Morrison calls an inability to control compulsions among serial killers is similar to impulsivity, and what she views as their inability to comprehend what they're doing is like the psychopath's apparent inability to process emotional data. There really isn't much difference, except that Morrison, as a frequent expert for the defense, wants to argue that serial killers cannot appreciate what they're doing and cannot stop, which would make them legally insane.

In the final chapter, Morrison lists nine traits that she believes all serial killers share. For example, she thinks they tend to be chatty hypochondriacs without remorse who are addicted to brutal acts that result in the deaths of others. They come across as charming but their act inevitably breaks down. They have no personality structure and no control over their behavior. They cannot be rehabilitated, in part because they're psychologically still at the infancy stage.

Significant among the list of traits is her claim that serial killers have no motive. That's rather odd in light of the fact that many have admitted to having motives that range from lust to anger to thrill to punishment. One man killed to stop earthquakes. Another, because his blood was turning to powder. A third, to punish prostitutes. Does she believe they just don't realize that they have no motives?

Two glaring issues are 1) Morrison's claims are based mostly on those whom she has interviewed for defense attorneys (and they have had good reason to put on an act for her), and 2) this is not a large enough population on which to base some of the claims she makes. (She says 80, but there's no evidence that she has done extensive testing on that many.)

Her book does not really work as the final answer on the nature of a serial killer, but she does offer some productive directions for brain research in the future. Nevertheless, her belief that it will all turn out to be a genetic abnormality is just that: a belief. Her tentative promise in the beginning that she will explain how this phenomenon may one day be stopped is, by the end, less than convincing.

For those who think serial killers are indeed human and that they show a diverse range of behaviors, motives, backgrounds, and disorders, the definitive book has yet to be written.