Forensic experts take on the NAS concerns about fingerprint examiners’ disagreement.

Fingerprint Examiners Found to Have Very Low Error Rates {By a group of 109 government fingerprint experts

Investigations into the reliability of fingerprint matches continues. This news release from a NIJ funded project states a strong position for its reliability (in its essence, everyone agrees in this study). Following this is a link to what the National Academy of Sciences 2009 report outlined regarding their concerns. To be fair, the NAS stated multiple areas of necessary research should be done. Among them were quality control and minimum thresholds of detail necessary for a positive comparison to be achieved. This PR report is silent as to whether this study actually sought to investigate aspects of validity (prints are all unique/ no two prints are ever the same) and assumptions print experts still make in order get into court. The NIJ spokeperson’s quote about this study wrapping-up all of these in one research package is a bit of forensic puffery. But this is forensic science right? 

WASHINGTON, Feb. 2, 2015/PRNewswire-USNewswire/ — A large-scale study of the accuracy and reliability of decisions made by latent fingerprint examiners found that examiners make extremely few errors. Even when examiners did not get an independent second opinion about the decisions, they were remarkably accurate. But when decisions were verified by an independent reviewer, examiners had a 0% false positive, or incorrect identification, rate and a 3% false negative, or missed identification, rate. The study was released today and funded by the Office of Justice Programs’ National Institute of Justice (NIJ).

“The results from the Miami-Dade team address the accuracy, reliability, and validity in the forensic science disciplines, a need that was identified in the 2009 National Academies report, Strengthening Forensic Science in the United States: A Path Forward.” Said Gerald LaPorte, Director of NIJ’s Office of Investigative and Forensic Sciences.

The research team, from the Miami-Dade Police Department Forensic Services Bureau Fingerprint Identification Section, tested the accuracy of 109 fingerprint examiners from 76 federal, state and local law enforcement agencies from across the United States. Examiners were presented with a variety of comparison challenges with varying degrees of difficulty. The study also measured how often individual examiners repeated their own decisions and how often different examiners came to the same conclusion.

 National Academy of Science Report on Fingerprints (2009) stated the following about fingerprints: This starts on page 136.

Page 139 has a section stating the NAS concerns about subjective phases of fingerprint comparisons.

 The NAS wrote:

Note that the ACE-V method does not specify particular measurements or a standard test protocol, and examiners must make subjective assessments throughout. In the United States, the threshold for making a “source” (comment: i.e. the perpetrator or person of interest) identification is deliberately kept subjective, so that the examiner can take into account both the quantity and quality of comparable details. As a result, the outcome of a friction ridge analysis is not necessarily repeatable from examiner to examiner. In fact, recent research by Dror  has shown that experienced examiners do not necessarily agree with even their own past conclusions when the examination is presented in a different context some time later.

About csidds

Dr. Michael Bowers is a long time forensic consultant in the US and international court systems.
This entry was posted in fingerprints, Forensic Science Bias, Wrongful Conviction and tagged , , , . Bookmark the permalink.

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