A mainstay of forensic science is on trial. Almost everyone accepts unquestioningly the power of fingerprint evidence in criminal investigation. Yet there appears to be no scientific justification to the assertion that each person’s fingerprints are unique. Moreover, fingerprint examiners rely on fragmentary, blurred, smeared and overlapped prints. They then proceed to
avoid statistics, rely on mere hunches,
and then …couch their conclusions in terms of absolute
certainty. The strongly held belief among FPEs that latent
fingerprints can be matched to one person alone, wrote David
Stoney in a 1997 legal practice manual, is “the product of
probabilistic intuitions widely shared among fingerprint examiners,
not of scientific research. There is no justification based on
conventional science, no theoretical model, statistics, or an
empirical validation process.”
The reliance on fingerprint evidence was nearly struck down in a recent court case, and there’s probably more to come. Lingua Franca
