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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 for dealing with close non-matches.  They discuss a few examples and talk about the relevant research on this topic.

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. Kim Connick.  Glenn and the guests talk about their time at the recent European Academy of Forensic Science (EAFS) conference in Dublin in May 2025.  The examiners from FSI discuss their research, posters, and presentations from EAFS.  Eric is also curious about their new AFIS system and has lots of questions about their processes.  The guests discuss forensic fingerprint practices in Ireland and especially working in their new national laboratory. Forensic Science Ireland: https://forensicscience.ie/ Dr. Kim Connick: [email protected]

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 incomplete, and various off-shoots of these questions.  The guys discuss the theoretical basis and some of the legal issues that arise in both the U.S. and Australia.

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 in Episode 282, and now wanted to dig in a bit into the appendices and take another look at some trends. Brendan offers his insights and shows that he’s pretty proficient with a spreadsheet too! The guys go back and forth discussing the strengths and limitations of the study and where the methodology and practice has likely improved since the original Black Box study (conducted in 2009). Article is available for free at: doi.org/10.1016/j.forsciint.2025.112457

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 papers further support our field and our conclusions.

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 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 dived into before: Simultaneous Impressions. They talk about different scenarios that can occur such as: some impressions stand alone, none stand alone, aggregation of features, and physical gaps or voids in an impression. They review the famous Mass v. Patterson case from 2005 that started the initial controversy in the field. They also have a chance to discuss John Black’s JFI research article from 2006 and other source material on the subject. Reference: Black, J.P. Pilot Study: The Application of ACE-V to Simultaneous (Cluster) Impressions. Journal of Forensic Identification, 56(6) Dated: November/December 2006 Pages: 933-971.

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

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 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!

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 summarize some of their standout lectures that they attended. Glenn then discusses how the Double Loop Podcast vendor booth went with Rebecca Coutant running it during the conference. Rebecca also was “Our Girl Friday”, doing her impromptu interviews with conference attendees.

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