The book makes the case that most serial killers are not guilty of their crimes by reason of insanity , and that they are incapable of understanding the evil of their actions , despite being , in many cases , highly functioning individuals in society .
The book makes the case that most serial killers are not guilty of their crimes by reason of insanity . 
 And that they are incapable of understanding the evilness of their actions , despite being , in many cases , highly functioning individuals in society .