Fingerprint Error Rate on Close Non-Matches

21 Pages Posted: 21 Sep 2020

Date Written: August 11, 2020


The accuracy of fingerprint identifications is critically important to the administration of criminal justice. Accuracy is challenging when two prints from different sources have many common features and few dissimilar features. Such print pairs, known as close non-matches (CNMs), are increasingly likely to arise as ever-growing databases are searched with greater frequency. In this study, 125 fingerprint agencies completed a mandatory proficiency test that included two pairs of CNMs. The false-positive error rates on the two CNMs were 15.9% (17 out of 107, 95% C.I.: 9.5%, 24.2%) and 28.1% (27 out of 96, 95% C.I.: 19.4%, 38.2%), respectively. These CNM error rates are (a) inconsistent with the popular notion that fingerprint evidence is nearly infallible, and (b) larger than error rates reported in leading fingerprint studies. We conclude that, when the risk of CNMs is high, the probative value of a reported fingerprint identification may be severely diminished due to an elevated false positive error risk.

Keywords: fingerprint accuracy, error rate, close non-match, fingerprint, fingerprint identification, proficiency test, false-positive

Suggested Citation

Koehler, Jonathan J. and Liu, Shiquan, Fingerprint Error Rate on Close Non-Matches (August 11, 2020). Available at SSRN: or

Jonathan J. Koehler (Contact Author)

Northwestern University - Pritzker School of Law ( email )

375 E. Chicago Ave
Chicago, IL 60611
United States

Shiquan Liu

China University of Political Science and Law ( email )


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