Double Loop Podcast

Eric and Glenn finish this two-parter episode about ASB Standards and Best Practice Recommendations. Specifically, in Part 2, they cover ASB Standard 015 "Standard for Examining Friction Ridge Impressions" (2024) and ASB Best Practice Recommendation 166 "Best Practice Recommendation for Comparison and Evaluation of Friction Ridge Impressions" (2024). The guys discuss how to use the standards, thei...

Eric and Glenn start off this supersized two-parter topic with a Regional Quirkisms game of Canadian-isms.  Then they move past the Great White North and talk about ASB Standards and Best Practice Recommendations.  Specifically, they cover ASB Standard 015 "Standard for Examining Friction Ridge Impressions" (2024) and in Part 1, cover ASB Best Practice Recommendation 165 "Best Practice Recommendat...

Eric and Glenn start the episode with a listener email and then play a numbers themed game of Regional Quirkisms.  For the topic of this episode, the guys discuss a 2025 paper from Simon Cole and Justin Sola titled "First impressions matter: Mundane obstacles to a forensic device for probabilistic reporting in fingerprint analysis".  The article discusses practical and realistic obstacles and hurd...

In this episode, the guys start off with some Michigan Regional Quirkisms.  They then review a 2024 paper titled "The effects of cognitive bias, examiner expertise, and stimulus material on forensic evidence analysis" by Michelle Pena, Stephanie Stoiloff, Maria Sparacino, and Nadja Schreiber Compo, from the Journal of Forensic Sciences (2024; 69:1740-1757).   The research paper provided lay partic...

Glenn Langenburg and Eric Ray interview Angela Tonietto about her recent article on the frequency of patterns in palm prints. ("Patterning in the Distal Portions of the Palms as a Key to Palm Print Identification". 2025, 75-3, p.274.) The research analyzes the frequency of loops and deltas in the interdigital area and compares the results to past research. (Link mentioned in episode: https://demo....

Happy New Year 2026!  The boys are back in town, with a new game: Regional Quirkisms.  After discussing Minnesota quirkisms, the guys answer a listener question from Ireland: "What's the most number of corresponding minutiae that you have seen from two impressions from different sources?".  This leads to a deep dive on close non-matches.  The guys share their tips, tricks, and red flag warnings fo...

Eric Ray and Glenn Langenburg talk about their week in Orlando at the 2025 IAI Educational Conference. Hear about Quality Metrics, limited examinations, and linking cases together, and hear from some of the conference attendees.

In this episode Eric poses to Glenn a Mandela effect question concerning household cleaning products.  After that, the guys celebrate the 4th of July holiday by welcoming their guests from Ireland.  Four fingerprint examiners from Forensic Science Ireland (FSI), the national forensic lab in Ireland, join the podcast.  The guests are Dr. Aoife Power, Dr. Craig Mullen, Mr. Columb Doherty, and Dr. Ki...

In this episode, the guys start with a product-based Mandela effect question.  Then they welcome back long-time friend of the show and webmaster, Michael Whyte from the New South Wales police force in Australia.  Michael has a question for Glenn and Eric, regarding latent-to-latent comparisons, using latent prints as 'proxy exemplars' when the exemplars are worse than the latent prints or incomple...

In this episode, Eric stumps Glenn with a geography based Mandela Effect question. Then the guys welcome their guest commentator, Brendan Max, Public Defender and Chief of the Forensic Science Division in Chicago, Illinois. Eric, Glenn, and Brendan take a second look at the 2025 FBI/Noblis follow-up black box study for latent fingerprints. The guys had previously done a cursory review of the paper...

Glenn Langenburg and Eric Ray review two articles from Cell that focus on the genetic basis for ridge development and pattern formation. 'The developmental basis of fingerprint pattern formation and variation' by Glover, et al., and 'Limb development genes underlie variation in human fingerprint patterns' by Li, et al. Our understanding of these complex processes continues to grow, and these paper...

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...

Eric Ray and Glenn Langenburg pay tribute to our colleague and friend. Kasey Wertheim passed away on March 7, 2025 and will be greatly missed. Please join us as we remember his legacy and contributions to the field of fingerprints and tell a few personal stories.

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 episode Glenn and Eric catch up after some hectic travel from recent weather issues. They do some news updates and also Eric had advice for new Patreon subscribers. Then they play an Oscar-themed round of “A Truth, a Lie, and a Mandela Effect” because it is the weekend of the 2025 Oscars. Then the guys tackle a topic which has come up many times in the past, but they’ve never actually dive...

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 f...

Glenn and Eric interview Sarah Chu, director of policy and reform with the Perlmutter Center for Legal Justice's (PCLJ) forensic science policy initiatives. Sarah breaks down her doctoral thesis on quality management and oversight in forensic science laboratories.

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 f...

The guys start out with a quick explanation of why Glenn’s sound is so bad (he’s in Switzerland recording). They also start the new “season”, post-IAI with a new game: "Truth, Lie, or Mandela Effect?" Eric talks about his fall conference junket and then the guys finally catch up on the IAI. They discuss their favorite lectures, workshops, and activities at the 2024 IAI Conference in Reno, NV. They...

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 pro...

Glenn and Eric are joined by Angela Hilliard to discuss her experiences with a cold case from the Pacific Northwest. Genetic genealogy provided a suspect's name from a cold case double homicide, and a latent palm print was left on the victim's van. Angela walks us through her initial erroneous exclusion, the subsequent identification, court testimony, and the resulting press coverage. A must-liste...

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...

Eric and Glenn start the episode with a Where in the Whorld that leads to a little catching up. Glenn was in NYC recently (saw the Harry Potter show on Broadway, indulging his “magician” side) and Eric has been doing the conference circuit. Eric is also soliciting fingerprint experts for a research project on ‘estimating image resolution’ based on ridge density. The guys also got a listener voicem...

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 mar...

Today Eric and Glenn start Part 1 of a two-parter on the 2023 Report of the Texas Forensic Science Commission dealing with a latent print case. First the guys do some catching up and play Where in the Whorld. They also discuss an email from Simon Cole and inquire on the impact of the recent AI paper on fingerprints. Then they discuss the TFSC report that followed an investigation into a complaint...