The individualization fallacy in forensic science evidence

Forensic scientists across a broad array of sub-specialties have long maintained that they can link an unknown mark (e.g., a partial fingerprint or tireprint) to a unique source. Yet no scientific basis exists for this assertion, which is sustained largely by a faulty probabilistic intuition equating infrequency with uniqueness. This Essay traces the origins of the individualization claim and explicates the various failed lines of evidence and argument offered in its support. We conclude with suggestions for improving the scientific bases of the forensic identification sciences.