Fingerprint evidence has long been considered an infallible form of proof, powerful enough to support a criminal conviction even without any other evidence. But when top experts manage to blow an important identification, our longstanding faith in fingerprints must be questioned. Fingerprinting, unlike DNA evidence, currently lacks any valid statistical foundation. This is gravely troubling. The growing size of computer fingerprint databases makes this issue still more acute. As a database grows in size, the probability that a number of people will have strikingly similar prints also grows. Because experts are permitted to testify about "100 percent positive" matches and to claim in court an error rate for the technique of zero, they have little incentive to support any research. No matter how accurate fingerprint identification turns out to be, it cannot be as perfect as they claim. Bruce Schneier must be all over this. The Achilles' Heel of Fingerprints | 
