azoblue (842509) writes "Even when analysts agree that someone could be a match for a piece of DNA evidence, the statistical weight assigned to that match can vary enormously, even by orders of magnitude. For instance, in one man's trial the DNA evidence statistic ranged from 1/95,000 to 1/13, depending on the different weighing methods used by the defense and the prosecution." Link to Original Source
The best book on programming for the layman is "Alice in Wonderland";
but that's because it's the best book on anything for the layman.