Validity and reliability of forensic firearm examiners.

\n In the past decade, and in response to the recommendations set forth by the National Research Council Committee on Identifying the Needs of the Forensic Sciences Community (2009), scientists have conducted several black-box studies that attempt to estimate the error rates of firearm examiners. Most of these studies have resulted in vanishingly small error rates, and at least one of them (D. P. Baldwin, S. J. Bajic, M. Morris, and D. Zamzow. A Study of False-Positive and False-Negative Error Rates in Cartridge Case Comparisons. Technical report, Ames Lab IA, Performing, Fort Belvoir, VA, April 2014.) was cited by the President’s Council of Advisors in Science and Technology (PCAST) during the Obama administration, as an example of a well-designed experiment. What has received little attention, however, is the actual calculation of error rates and in particular, the effect of inconclusive findings on those error estimates. The treatment of inconclusives in the assessment of errors has far-reaching implications in the legal system. Here, we revisit several black-box studies in the area of firearms examination, investigating their treatment of inconclusive results. It is clear that there are stark differences in the rate of inconclusive results in regions with different norms for training and reporting conclusions. More surprisingly, the rate of inconclusive decisions for materials from different sources is notably higher than the rate of inconclusive decisions for same-source materials in some regions. To mitigate the effects of this difference we propose a unifying approach to the calculation of error rates that is directly applicable in forensic laboratories and in legal settings.

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1087&context=csafe_pubs

Treatment of inconclusives in the AFTE range of conclusions

Cognitive biases in the peer review of bullet and cartridge case comparison casework: A field study.

Committee on science, technology, and law

https://doi.org/10.1016/j.fsisyn.2022.100221

Planning, design and logistics of a decision analysis study: The FBI/Ames study involving forensic firearms examiners

https://scholarlypublications.universiteitleiden.nl/access/item%3A2906701/view

F.W. Didden

Papers

A part-declared blind testing program in firearms examination.