Violating the Law of Probability

VIOLATING THE LAW
OF
PROBABILITY



As a forensic scientist, I have been exceptionally interested in the concept of probability, which, to me, has been a major cornerstone underlying the practice of criminalistics. The criminalist is confronted with the classic questions, including who, what, why, when, where, and how. One of the major activities in this occupation is the comparison of objects, usually to determine whether they have a common origin which might serve to indicate possible involvement or innocence regarding an unsolved crime. Examples of the kind of questions which arise are:
Was this bullet fired from this gun?
Was this mark made by this tool?
Did this bloodstain come from the victim?
Was this bite mark made by the suspect’s teeth?
And, as you might imagine, there are hundreds of similar questions which the forensic scientist is called upon to attempt to resolve. And the decision as to whether or not there is a positive correspondence will really boil down to the establishment of a probability. This is based upon the presence or absence of numerous similar characteristics in the exemplars which are being compared.
It is not my intention to devote this paper to the practice of criminalistics, although that would be a fascinating subject. I simply wanted to indicate how the concept of probability came to be of considerable interest to me. Actually, I have been amazed at certain events which I have experienced in my own lifetime; events which, at least to me, would seem to be highly improbable. I would like to emphasize at this point, that I do not place mystical or supernatural forces behind these events, although others may wish to do so. Nor do I believe that I am in any way special with regard to such happenings. I suspect that many persons have had similar unlikely experiences, and I would welcome hearing from such people.

Episode One: An improbable discovery.
I was not quite three years old. My mother had died following the birth of my brother. We had two half-sisters a few years older. My father, who sold fruit from a horse and wagon, was unable to care for us, and we were placed in a children’s home in Denver, Colorado. My father dropped out of sight, and in the following years we heard nothing more from him. We grew up without knowing whether he was dead or alive, and we were treated effectively as though we were orphans. At the age of fifteen or sixteen, my sisters were farmed out as domestic servants. This was now the heart of the great depression. My sister Edith found the domestic servant role unbearable and ran away. She was now sent to the girls reformatory at Morrison, Colorado. When she was finally released, she hit the road, riding freight trains and bumming around the country, trying to survive.
Now she was wandering down a street in Albuquerque, New Mexico. She spotted a crumpled envelope lying in the gutter. Out of mere curiosity, she picked it up. Who knows what might be inside? It turned out that it was empty. But when she looked at the writing on the face of the envelope, she was able to discern my father’s name.
I have no idea whether it was sent to him, or whether he was the sender. Nor do I know anything about the age of the envelope, although for the writing to still be legible, it must have been of fairly recent origin. Now we knew that at least he was alive up to this point in time. We would no longer consider ourselves to be orphans.
At the age of 17, I graduated from high school and left the Home . I was out in the world, and to this day I am grateful that I was able to join the CCC,
( Civilian Conservation Corps), a great government program that was the salvation of many a poor kid. It was at this time that I finally heard from my father. Yes , he was alive in El Paso, Texas. He had a truck and traveled around the southwest, trading with the farmers in that region. For your information, I finally met him when I was in the army during the war.
But I have always thought of the freakish circumstance of my sister wandering down a hot, dusty street in Albuquerque and picking up a dirty envelope which allowed us to know that our father was still alive.
What is the probability of such an occurrence?
In my next blog, I will describe another event, which, to me seemed to stretch the laws of probability. In the meantime, I would be delighted to hear from any reader who might have gone through a similar experience.