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The Individualization Fallacy In Forensic Science Evidence, Michael J. Saks, Jonathan J. Koehler

Vanderbilt Law Review

Forensic identification science involves two fundamental steps. The first step is to compare a questioned item of evidence to an exemplar from a known source and judge whether they appear so alike that they can be said to match. The second step is to assess the meaning of that reported match: What is the probability that the questioned and the known originated from the same source?

Different risks of error are present at each step. The risk of error in the first step is that a reported match between a questioned and a known sample might not really match. Even …