A very bad application of probability theory at that. We know that a single hair of Danielle's was found in the sink trap of the motor home. We know there are multiple ways it could have gotten there, simply because we are able to imagine multiple ways, and don't actually know the answer. The sum of the probabilities of all the ways it could have gotten there must be equal to 1.
This, then is the calculation that you're really interested in - not some single path theory. It's a much more difficult problem (in fact, it's not solvable, since you must assign a probability to the paths you have not thought of). But then, that's why we don't put probability evidence in a courtroom, and why it's not taken too seriously on these boards.
Drew Garrett
I am going by the ways I was told it happened here.
I was told it 1). Fell off during her play time visit, 2) was washed up by Westerfield, 3) Was deposited in the sink. Based on this there would have to have been the stated events.
The sum of the probabilities of all the ways it could have gotten there must be equal to 1.
I agree and the idea that it got there by her playing hide and seek doesn't add up.
First, I concede you are smarter about math and statistics and probability, than I am. Second, let me agree that the complexity is why it isn't in courtrooms.
My point is this: People do it, very generally, when they arrive at their own conclusions.
For some folks, it is very much like a probability calculation, eg. based on an assesment of facts, chances, etc.
For others, they skip most of the facts and probabilities, and go with emotion, intuition. Each type of juror gets a vote, so the prosecution and defense are wise to play the case to each type of juror.