• The New Wigmore, A Treatise on Evidence: Expert Evidence, 2024 Cumulative Supplement, New York: Wolters Kluwer, with D. Bernstein & M. Wittlin. 237 pp.

• Reference Guide to Statistics and Research Methods, in Reference Manual on Scientific Evidence, National Research Council Committee on the Development of the Fourth Edition of the Reference Manual on Scientific Evidence ed., Washington D.C.: National Academy Press, with H. Stern (in press)

• Reference Guide on Human DNA Evidence, in Reference Manual on Scientific Evidence, National Research Council Committee on the Development of the Third Edition of the Reference Manual on Scientific Evidence ed., Washington DC: National Academy Press, 4th ed. (in press)

• Statistical Genetics in the Courtroom, Statistical Genetics Symposium, University of Washington, Seattle, WA, July 15, 2023

• Close Encounters of Various Kinds: Developments in Forensic DNA Science and the Law, 29th Congress of the International Society for Forensic Genetics, Wash. DC, September 1, 2022 (keynote lecture)

• Applying Legal Rules of Evidence to Address Error and Bias, Gordon Research Conference on Forensic Analysis of Human DNA, Mt. Snow, VT, June 23, 2022

• Toolmark-comparison Testimony: A Report to the Texas Forensic Science Commission, May 2, 2022 (with the student members of the Yale Law School Forensic Science Standards Practicum)

• National Institute of Standards and Technology, Organization of Scientific Area Committees for Forensic Science (OSAC) Forensic Science Standards Board member and Affiliate, Legal Task Group and Statistics Task Group

• National Institute of Standards and Technology Expert Working Group on Human Factors in Forensic DNA Interpretation member

• Visiting Professor, Yale Law School, Spring 2022

The National Institute of Standards and Technology (NIST) has announced that it will host a workshop "on a new Scientific Foundation Review for footwear impression examination ... at the 2023 International Association for Identification (IAI) ... conference" on Aug. 25. "NIST Scientific Foundation Reviews document and evaluate the scientific basis for forensic science methods and practices." Originally discussed in 2016, so far NIST reviews have resulted in final reports on two topics — digital evidence and "bitemark analysis" (which is to say, bitemark comparisons).

Michelle Taylor, Establishing the Foundation of Reliable Duct Tape Evidence, Forensic News, Aug. 7, 2023, https://www.forensicmag.com/599113-Establishing-the-Foundation-of-Reliable-Duct-Tape-Evidence/

A professor at West Virginia University is calling attention to an overlooked element of trace evidence: duct tape.

“Duct tapes, in particular, are used very often to gag victims,” said Tatiana Trejos, assistant professor in the West Virginia University Department of Forensic and Investigative Science. “So, when we have traces that are left, they can tell us about who was there, who tore it apart and so forth.”

The problem is, there’s no standardized protocol or industry accepted guidelines for the analysis of duct tape. Trejos hopes to change that. She and graduate student Meghan Prusinowski have developed a one-of-a-kind method that provides a systematic approach for comparing pieces of trace evidence that appear to be from the same source—including duct tape.

When a material like duct tape is separated into pieces, it leaves “fracture edges,” which can be evaluated and examined to see if there is a physical fit. A physical fit is putting the two fracture edges together and demonstrating that they have enough individual characteristics to indicate that they were once together, explained Trejos. This type of evidence tends to be reliable, especially given the random nature of edge fractures.

“It is very unlikely that we can reproduce all the microscopic features of a torn edge,” said Trejos. “We can tear apart thousands and thousands of pieces, and we have demonstrated it’s very unlikely that there will be, just by random chance, a perfect fit in pieces that were not once together.”

The new method allows examiners to qualify and quantify features and characteristics that are commonly observed during physical fit examinations. Then, the examiners follow the criteria to provide a score metric of how similar the tape edges are, estimate probabilities and use an Excel template to systematically document the features of the physical fit.

Testing the method, Trejos and her students found the error rate was extremely low in duct tape physical fit examinations. The next step, she said, will be to teach forensic examiners how to follow the method.

“Historically, examiners have been very good at correctly identifying fits,” Prusinowski said. “But until recently, there hasn’t been much research identifying what can cause misidentifications, and there really haven’t been many studies that recommend a particular method for edge comparisons.”

The team has already led a series of interlaboratory studies to test the method using practitioners involved in physical fit examinations for years or even decades; but there’s more to come.

Prusinowski said the established guidelines will also help researchers focus on pattern recognition in other trace evidence materials.

The next step will be to provide other forensic labs with the scientific foundation the West Virginia University team has established.

“They’ll have all the resources they need to present evidence in court,” Trejos said. “Because that can make the difference between sending an innocent person to jail or not.

R. Chapman, S. Summersby, T. Lang, J. Raymond, K. Ballantyne, Novices Cannot Fill the Examiners’ Shoes: Evidence of footwear examiners’ expertise in shoe comparisons, 2023, Science & Justice, 63(5):598-611

Abstract: The value of a footwear examiner’s opinion centres on their ability to determine whether a particular shoe made an impression with greater accuracy than a novice. However, there has been limited research on the expertise of footwear examiners and the accuracy and reproducibility of their decisions. In the current study, we measured the accuracy and consensus of 31 footwear examiners versus a comparison group of 29 novices. Participants completed 20 ground truth known mock shoe comparisons. Results demonstrated that footwear examiners were more accurate than novices, regardless of comparison difficulty. Overall, on trials where probative decisions were given, examiners made false identifications and false exclusions on a total of 3% and 2% of trials, while novices made false identifications and false exclusions on a total of 19% and 17% of trials. Examiners also demonstrated better consensus in their opinions than novices, although both groups demonstrated low levels of agreement in their responses and variability in their interpretation of the conclusion scale. In summary, these findings support the proposition that footwear examiners show expert-level performance in matching known and unknown footwear impressions. These performance estimates may help the criminal justice system to appropriately value footwear examination evidence.

Keywords: Forensic footwear evidence; Footwear examiners; Expertise; Error rates; Accuracy; Reproducibility

Statistics in the Public Interest: In Memory of Stephen E. Fienberg (Alicia L. Carriquiry et al. eds. 2022) includes:

• J. B. Kadane, Bayes and the Law, pp. 141-152

• Hal S. Stern, Statistical Considerations for the Analysis and Interpretation of Forensic Evidence, pp. 153-167

• Danica M. Ommen & Christopher P. Saunders, Differences between Bayes Factors and Likelihood Ratios for Quantifying the Forensic Value of Evidence, pp. 169-186

• Karen Kafadar, Statistical Issues in Assessing the Reliability of Eyewitness Identification, pp. 187-206