KNOLL: Yes, this is entirely possible. Being a psychopath does not automatically make one a killer.
TAMBRA, Dallas: How do you recognize a person as being a psychopath? How do you know if you are acquainted with one in either your professional or personal life?
KNOLL: Please see my previous response to a similar question re: psychopathy. There is an excellent book you might be interested in that would give you an in-depth answer to your other question: "Without Conscience" by Robert Hare.
JIM, Lawrenceville, Ga: Doctor, personally, do you believe evil exists? If not, do you believe this is just a case of extreme human behavior? What percentage of the population is capable of such deeds?
KNOLL: Excellent question. For forensic purposes, it is my opinion that forensic psychiatrists have nothing to say about evil because it is a moral judgment subject to bias and not a scientific principle. I actually wrote a paper on this very subject (CLICK HERE to view) and here is the proper reference: Knoll J: The Recurrence of an Illusion: The Concept of "Evil" in Forensic Psychiatry. Journal of the American Academy of Psychiatry and the Law, 2008; 36(1): 105-116.
Since you asked my "personal" opinion, I will try to be austere and not wax too philosophical. I would only say that, in my personal experience, most of what people want to label "evil" is really extreme selfishness. For example -- in the case of a male sexually sadistic serial killer -- the experience of enhancing his orgasm is more important than his victim's life. What could be more selfish?
PAMELA, Henderson, N.Y.: Just watched the two-hour program, and my question is this: Wouldn't the "suicide letter" have shown exactly who it was who wrote it, the mother or daughter, through the phraseology and choice of words used, spelling errors, etc.? Not much discussion was given to this on the program.
KNOLL: Now you've hit on exactly what I wanted to get across. My role in this case was to do exactly what you have suggested: Use my forensic training, experience and forensic psycholinguistic expertise to analyze the alleged suicide letter. I did not testify in the case but gave my findings to the district attorney for him to use as he saw fit, which he did. This may not have come across much in the program.
I was able to carefully analyze the alleged suicide note, as well as compare it to samples of both Stacey's and Ashley's writing. In short, it was my opinion, based on my experience of reviewing over 200 genuine suicide notes, that the alleged suicide note was not written by Ashley, and that more likely than not, it was written by Stacey. While I cannot at this time outline all the reasons for my conclusions, here were a few:
The note contained many findings that are atypical for genuine suicide notes
The linguistic data revealed similar, if not identical, idiosyncratic grammar and word usage in both the note and Stacey's writing samples.
There was a high frequency in the note of uneccesarily repeating the theme of Stacey's nonresponsibility for the murder. For example, the theme: "It was me [Ashley] who did it, not you [Castor]," is repeated an excessive number of times in a one page note.
The note contained an apparent gratuitous explanation of the details of the crime, and in such a manner as to strongly suggest the putting forth of an alibi.