Double Loop Podcast

In this episode, Glenn and Eric start with a quick game of “A Truth, A Lie, and a Mandella Effect”. Then they pose a question from a listener regarding interest in a forum where listeners can go and discuss the episodes of the show, ask questions, and chat “amongst themselves”. Finally they get to the long awaited Noblis/FBI study “Black Box 2” latent fingerprint error rate study. This is a re-do of the 2011 black box study for latent fingerprint performance. This study “Accuracy and reproducibility of latent print decisions on comparisons from searches of an automated fingerprint identification system” by Hicklin, Richetelli, Taylor and Buscaglia (For Sci Intl, 370 (2025), 112457), reported the performance of 156 U.S. latent print examiner participants each reviewing about 100 latent prints/comparisons resulting in over 14,000 trials. The study reports numerous statistics of performance such as sensitivity (63%), specificity (70%), false positive error rate (0.2%), and false negative error rate (4.2%). The guys also discuss some important study design differences, plus there are a lot of data in the appendices. Finally they talk about the number of false positives made in the study (n=23) and the fact that 13 of those 23 were made by one participant and how that impacted the results. Article is available for free at: https://doi.org/10.1016/j.forsciint.2025.112457

Eric Ray and Glenn Langenburg pay tribute to our mentor and friend. Pat Wertheim recently passed and will be greatly missed. Please join us as we remember his legacy and tell a few stories.

In this first recorded episode of 2025, Eric and Glenn start with Eric being pedantic in his “A Truth, A Lie, and a Mandela Effect”. The guys catch up on New Year stuff and then launch into a review of a research paper from New South Wales, Australia, titled “How often do fingerprint examiners disagree in routine casework?” by O’Connor and Chapman (2024) from Forensic Science International. Eric first discusses some of the important differences in casework workflow and conclusions between Aussie examiners and U.S. examiners. Then they discuss the results of the paper and the significance of the findings. At the end, they discuss solutions and ideas for resolving conflict and ultimately find that conflicting results and examiner disagreements are a normal, expected, natural part of the examination process. Find the paper at: https://doi.org/10.1016/j.forsciint.2024.112139

In this episode the guys discuss historical figures in the field of fingerprints. At the top of the episode Eric gives Glenn an Australian themed “A Truth, a Lie, and a Mandela Effect”. Glenn tells a couple of stories from his trip to London, which also inspired the topic for the episode. Because of Glenn’s time in Switzerland this fall reading old texts, he learned a lot about the early days of fingerprints. The guys discuss contributions, stories and cases from Juan Vucetich, Sir Francis Galton, Sir Henry Faulds, Sir Edward Henry, Alphonse Bertillon, Dr. Edmond Locard, and more!

Eric and Glenn are back from a little summer break, prepping for the 2024 IAI Conference in Reno. They do a final “Where in the Whorld?” game. Then they jump into a recent paper on “Inconclusive” decisions (Swofford, et al. (2024) “Inconclusive Decisions and Error Rates in Forensic Science”, Forensic Science International: Synergy (vol 8; 100472)) authored by several members of NIST. The paper proposes a method for computing and communicating error rates when “inconclusive” decisions are made. The paper also focuses on making clear distinctions between “method performance” versus “method conformance”. The guys discuss their views on the method and the implications the paper may have for fingerprint examiners and their agencies. Swofford, H. , Lund, S. , Iyer, H. , Butler, J. , Soons, J. , Thompson, R. , Desiderio, V. , Jones, J. and Ramotowski, R. (2024), Inconclusive Decisions and Error Rates in Forensic Science, Forensic Science International: Synergy, [online], https://doi.org/10.1016/j.fsisyn.2024.100472, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957335 (Accessed August 31, 2024) Link to open source paper here: https://doi.org/10.1016/j.fsisyn.2024.100472

This super-sized episode has the guys interviewing several people from a recent Expert Working Group on Human Factors in the discipline of DNA. Glenn starts by giving Eric his “Where in the Whorld” question and they catch up on some recent travels. Glenn also explains why this episode does NOT feature a continuation of the previous episode on the Peacemaker case, but instead pivots to a different DNA topic. In May 2024, NIJ/NIST released a Human Factors and Forensic DNA Interpretation report. (The) Niki Osborne, Ph.D., the project lead and contractor for NIST (Natl Institute of Standards and Technology) describes how the project came to be and how NIST selected the Expert Working Group (EWG). Then, two members of the EWG, Jarrah Kennedy, Assistant DNA Supervisor, Kansas City Police Crime Laboratory, and Michelle Madrid, DNA Technical Leader, Los Angeles County Sheriff’s Department, discuss the various recommendations in the report. The group covers all sorts of fun topics within DNA discipline such bias, new software and computational approaches, activity level, implementation, enforcement, and so forth. The episode ends with Niki and Glenn discussing other disciplines and future reports. Links to the free report: Expert Working Group on Human Factors in Forensic DNA Interpretation (May 2024). Forensic DNA Interpretation and Human Factors: Improving Practice Through a Systems Approach. National Institute of Standards and Technology, Gaithersburg, MD, NIST IR 8503. http://doi.org/10.6028/NIST.IR.8503 https://nvlpubs.nist.gov/nistpubs/ir/2024/NIST.IR.8503.pdf Guests: Nikola Osborne, Ph.D., NIST Contractor, and Project Lead for the Expert Working Group. Jarrah Kennedy, Assistant DNA Supervisor, Kansas City Police Crime Laboratory Michelle Madrid, DNA Technical Leader, Los Angeles County Sheriff’s Department

Today Eric and Glenn finish Part 2 on the 2023 Report of the Texas Forensic Science Commission dealing with a latent print case. They continue to discuss the TFSC report that followed an investigation into a complaint filed against the latent print contractor(s) in the Joseph Webster case. In part 2, the guys focus on Glenn's examination which concluded that the Webster palm mark was a complex mark and that 3 critical things will shape the conclusion rendered by an examiner: 1) which images were used; 2) which features were relied upon; 3) how the examiner applied the ACE-V methodology. Finally, they discuss the over 2 dozen recommendations that the Commission made for fingerprint examiners in Texas to follow in latent print examinations. www.txcourts.gov/media/1457617/fi…-as-of-12623.pdf

Eric Ray and Glenn Langenburg sit down for a chat with Steve Johnson about face examiners, face comparisons, and the IAI. Steve's background includes latent prints, forensic art, face comparison, crime scene, and many positions with the IAI. He shares the future of the face discipline and how the IAI is working towards a certification process.