On its most essential level, criminology is about why people do the things they do; that is, it is about the human condition. And of all the millions of horrendous crimes that have been committed over the years, certain criminal cases seem to have lives of their own. Despite the passage of time, they continue their hold on our collective imagination, and our collective fears. For some reason, each of these cases and the stories surrounding them touches something deep in that human condition -- because of the personalities involved, the senseless depravity of the crime, the nagging and persistent doubts about whether justice was actually done, or the tantalizing fact that no one was caught. In any event, the case remains a fascinating and perplexing mystery and gets to the core of how we see ourselves as human beings and our relationship to society.

Each of the cases we'll be examining in this book has remained extremely controversial. And each of these cases contains some universal truth at its base to which we can all relate. Taken together, they present a panorama of human behavior under extreme stress and an inevitable commentary on good and evil, innocence and guilt, expectation and surprise.

Through the cases we'll examine, we hope to show the uses, benefits, and limitations of modern behavioral profiling and criminal investigative analysis as practiced by the behavioral science units of the National Center for the Analysis of Violent Crime at the FBI Academy in Quantico, Virginia. The operational division that actually does the profiling and case consultations has undergone several changes of name and designation. At the time that I was its chief until my retirement in 1995, it was known as the Investigative Support Unit, or ISU. Sometimes, we can go a long way in determining the identity of an unknown offender. Sometimes, we can only say who it is not. Sometimes, we can't do either. But we've greatly improved our ability to interpret forensic evidence from a behavioral standpoint. Had the discipline been around at the time of the earliest cases in this book, I believe we would have solved them and delivered the offenders to justice.

We will be focusing on several key themes that will be familiar to readers of our previous books. One is motive: why an individual decided to do what he did and how we try to determine that. Another is the evolution and development of the criminal: you don't just wake up one morning and commit any of these crimes without prior behavioral indicators and a specific precipitating stressor. A third is postoffense behavior: how an individual who has committed a serious crime may be expected to act and react afterward. All of these factors will go into our evaluations.

Let's get down to the nitty-gritty. Are we going to be able to "solve" each of these crimes that have tantalized and eluded experts for years, decades, or in two instances, more than a century?

Frankly, that's doubtful.

What we are going to do is to approach each one to some extent differently than it's been approached in the past. We're going to look at and examine each one as I would have as a profiler and criminal investigative analyst for the FBI. We're going to use the crimes and crime-scene evidence to indicate the type of individual we should be looking for. Then we'll evaluate the subjects -- those suspected, accused, and/or convicted of the crime -- to see how well they fit in.

In much of the revisionist-theory industry surrounding these cases, writers tend to decide what they think and then employ the evidence to support that theory. Then they essentially challenge skeptics to prove a negative. Among the examples of this phenomenon, which will become clear as you read on:

-- Why couldn't Mary Kelly's estranged husband have killed four of her friends to scare her into getting back with him, then killed her when she would not, and blamed it all on some mythical Jack the Ripper?

-- Why couldn't Emma Borden have secretly come back, snuck into her house, and killed her parents?

-- Why couldn't Patsy Ramsey have killed her daughter in a rage if she discovered the child was being molested by Patsy's husband? And why couldn't John Ramsey have been a molester?

Despite absolutely no evidence for any of these suppositions, despite a feeding frenzy of character investigation in all three cases, facts become almost irrelevant to certain "analysts."

"It could have happened that way" is good enough for some theorists. It won't be good enough for us. When there is a discrepancy in the evidence or more than one version of the same set of facts, we'll acknowledge that and see what we can do with it. Whatever we can determine or whatever we fail to determine, we're going to let the evidence lead us, not the other way around.

Okay? Then let's get started.