Double Loop Podcast

Glenn Langenburg and Eric Ray are joined by Todd Weller to discuss the firearms/toolmarks discipline. Todd was involved in the NY firearms case from Episode 227 and shares his experiences there. The guys then talk through accuracy studies for firearms examiners and similarities and differences between firearms and fingerprints. Lots to cover in an extra-long episode.

In this episode, Eric and Glenn are joined by Dr. Heidi Eldridge and Prof, Christophe Champod, the authors of "Testing the accuracy and reliability of palmar friction ridge comparisons - A black box study". The guests describe the design, the aims, and the results of the study. We get into discussions about the meaning and usefulness of error rate statistics and confidence intervals from performance studies such as this.

Link to the Article (open source):

http://dx.doi.org/10.1016/j.forsciint.2020.110457

Link to study results in shinyapp:

https://cchampod.shinyapps.io/Results_BBStudy/

Link to confidence interval tools in shinyapp:

https://cchampod.shinyapps.io/app_CI/

Link to error rate primer prepared by Champod, Eldridge, Lambert:

zenodo.org/record/3734560#.YB8Ki5NKhbt

Glenn Langenburg and Eric Ray finally get back on track with a review of a recent article on GYRO markings. "Evaluating the Accuracy and Weight of Confidence in Examiner Minutiae Annotations" was written by Jeremy John and Henry Swofford and published in the JFI. The study measured whether examiners placed minutiae markers on true minutiae using Green, Yellow, and Red markers. It then compared the color choices of examiners against the color choices of the automatic LQMetric and DFIQI algorithms. Eric and Glenn will soon be publishing videos of themselves conducting comparisons, using GYRO, and discussing their similarities and differences. Keep an eye out for those coming soon. Also, the 8pm (ET) Wednesday night virtual Happy Hour continues at https://discord.gg/b39pp6j

Glenn Langenburg and Eric Ray review the newest article from Austin Hicklin, Bradford Ulery, Madeline Ausdemore, and JoAnn Buscaglia. Why do latent fingerprint examiners differ in their conclusions? reviews data from the Black Box, White Box, and Eye Tracking papers, summarizes trends through all of that research, and recommends changes for the fingerprint field.

After some Halloween talk, Eric and Glenn discuss this episode’s research article: “The Utility of Expanded Conclusion Scales During Latent Print Examinations” by Carter, Vogelsand, Vanderkolk, and Busey in J Forensic Sciences (online, 2020). This study examines the results of 27 experts who completed 30 comparisons under a 3-point SWGAST scale versus 30 comparisons under a 5-point OSAC scale. The guys discuss error rates, changes in apparent decision thresholds, and the rate of misleading evidence of “support for…” decisions.

Article: https://onlinelibrary.wiley.com/doi/abs/10.1111/1556-4029.14298?af=R

Interpol Paper Reference: https://www.sciencedirect.com/science/article/pii/S2589871X20300139

In this Halloween episode, Eric and Glenn discuss a new paper published by Koehler and Liu titled “Fingerprint error rate on close non-matches” (Journal of Forensic Sciences, Sept. 2020). The paper raises a lot of discussion between the guys regarding close non-matches, inconclusives, training, and testimony. They each have a different take on some of the key issues in the paper, but in the end identify what common ground on which they agree.

Glenn Langenburg and Eric Ray pay special tribute this week to a giant in the fingerprint world, Bob Garrett. With the passing of Bob and a few other close friends and colleagues, Glenn and Eric want to look back at the contributions of Bob Garrett in particular. In his single year as president of the IAI, he was instrumental in responding to the NAS Report, addressing the McKie controversy, and moving forward the Standardization II Committee. Please join us in remembering Bob and all of the other friends and colleagues that we've recently lost.

In this episode, Glenn and Eric discuss a recent case Glenn was involved in: a knuckle-crease case. The case had a Daubert hearing in addition to trial testimony for jurors. The guys discuss if non-friction ridge skin associations would meet the Daubert factors. If you were preparing for such a hearing, what research and testing would you need to demonstrate expertise of the expert, or demonstrate reliability of the methods and principles? Does expertise in fingerprints using ACE-V translate to the comparison of non-friction ridge skin or any other objects you might encounter in photographs? Stay tuned…their answers may surprise you!

Glenn Langenburg and Eric Ray review a recent court decision on firearms testimony. NY v Ross was a recent Frye case where the testimony of firearms examiners was restricted to only class characteristics. Was this a fair decision? Did the judge raise good points? How does this case relate to latent print testimony and latent print accuracy studies? Join us for an hour of fun talk as we dive deep into the nerdy intersection of science and law.

https://legalaidnyc.org/wp-content/uploads/2020/07/Ross-Frye-Decision_Full-.pdf

Glenn Langenburg and Eric Ray were recently asked which latent print books they recommend the most. This episode they talk through the absolute creme de la creme of fingerprint tomes. New books, old books, green books, blue books. Whether you're developing or comparing ridges, we've got a list of what you need to read. Also make sure to join us Wed nights at 8pm EDT for Virtual Happy Hour at https://discord.gg/b39pp6j