Double Loop Podcast
Science & Ideas
About
Glenn Langenburg and Eric Ray discuss latent prints, the latest latent print research, forensic science in general, and regular interviews with people in the latent print field.
Episodes
- Episode 291 - Mundane Obstacles to Developing a Stats Model
The Double Loop Podcast episode discusses a 2025 paper by Simon Cole and Justin Sola examining mundane obstacles to creating a statistical model for fingerprint analysis. The paper explores practical, non-obvious challenges that hinder the…
- Episode 290 - Review of a Bias Research Paper
This episode reviews a 2024 study from the Journal of Forensic Sciences examining cognitive bias in fingerprint analysis. The research compared lay participants and fingerprint experts using varied stimuli and contextual information, findi…
- Episode 289 - Angela Tonietto Interview - Palm Patterns
Angela Tonietto was interviewed by Glenn Langenburg and Eric Ray about her article on the frequency of patterns in palm prints. The research analyzed loops and deltas in the interdigital area and compared results to previous studies.
- Episode 288 - Close Non-matches
The Double Loop Podcast discusses 'Regional Quirkisms' and answers a listener question about minutiae from different sources. The episode includes a deep dive into close non-matches, offering practical advice and discussing relevant resear…
- Episode 287 - IAI 2025 Review
In Episode 287 of the Double Loop Podcast, hosts Eric Ray and Glenn Langenburg review their experience at the 2025 IAI Educational Conference in Orlando. They discuss topics such as quality metrics, limited examinations, and linking cases,…
- Episode 286 - Forensic Science Ireland Interview
In this episode, Glenn and Eric interview four fingerprint examiners from Forensic Science Ireland regarding their experiences at the European Academy of Forensic Science conference. The guests discuss their research, the implementation of…
- Episode 285 - Michael Whyte Interview - Latent to Latent Comparisons
Michael Whyte discusses latent print comparisons and the use of 'proxy exemplars' with Glenn and Eric on the Double Loop Podcast. They explore the theoretical and legal aspects of this practice in both the US and Australia.
- Episode 284 - Black Box '22 - Part 2 (with Brendan Max)
In episode 284 of the Double Loop Podcast, Brendan Max, a Public Defender and Chief of the Forensic Science Division, joins hosts Eric and Glenn to re-examine the 2025 FBI/Noblis black box study on latent fingerprints. They discuss the stu…
- Episode 283 - DNA & Patterns
Glenn Langenburg and Eric Ray discuss two Cell articles, 'The developmental basis of fingerprint pattern formation and variation' and 'Limb development genes underlie variation in human fingerprint patterns,' exploring the genetic factors…
- Episode 282 - Noblis-FBI Black Box 2 Fingerprint Study
The Double Loop Podcast episode discusses the Noblis-FBI Black Box 2 study, which re-examines latent fingerprint error rates. It covers participant performance statistics, including sensitivity, specificity, and error rates, along with stu…
- Episode 281 Kasey Wertheim Tribute
A tribute to Kasey Wertheim, who passed away on March 7, 2025. Hosts Eric Ray and Glenn Langenburg honor his legacy and contributions to the field of fingerprints, sharing personal stories.
- Episode 280 - Pat Wertheim Tribute
Eric Ray and Glenn Langenburg reflect on the life and career of their mentor, Pat Wertheim. They share stories and remember his legacy following his recent passing.
- Episode 279 - Simultaneous Impressions
Glenn and Eric discuss the concept of simultaneous impressions, exploring various scenarios and referencing the Mass v. Patterson case and John Black's research from the Journal of Forensic Identification.
- Episode 278 - Aussie Paper on Examiner Disagreements
Hosts Eric and Glenn review the 2024 paper 'How often do fingerprint examiners disagree in routine casework?' by O’Connor and Chapman. They explore differences between Australian and U.S. forensic workflows and discuss how examiner disagre…
- Episode 277 - Sarah Chu Interview
This episode features an interview with Sarah Chu, director of policy and reform at the Perlmutter Center for Legal Justice. She discusses her doctoral thesis on quality management and oversight in forensic science laboratories.
- Episode 276 - History Episode - Stories of the Forefathers
The Double Loop Podcast episode delves into the history of fingerprint analysis, discussing the contributions and stories of key figures such as Juan Vucetich, Sir Francis Galton, and Sir Edward Henry. The episode also includes personal an…
- Episode 275 - 2024 IAI Conference: The Reno Recap
Eric and Glenn discuss their experiences at the 2024 IAI Conference in Reno, Nevada, highlighting favorite lectures, workshops, and activities. They also cover the podcast's vendor booth and attendee interviews.
- Episode 274 - NIST Inconclusive Paper
In Episode 274 of the Double Loop Podcast, hosts Eric and Glenn discuss a NIST paper proposing a method for calculating and reporting error rates when "inconclusive" decisions are made in forensic science. They examine the paper's distinct…
- Episode 273 - Angela Hilliard Interview - Erroneous Exclusions
Angela Hilliard joins Glenn and Eric to discuss a cold case involving a double homicide in the Pacific Northwest. The episode covers the identification of a suspect through genetic genealogy, the presence of a latent palm print, and Hillia…
- Episode 272 - DNA and Human Factors Expert Working Group Report
This episode discusses the May 2024 NIJ/NIST report on Human Factors and Forensic DNA Interpretation. Project lead Nikola Osborne, along with EWG members Jarrah Kennedy and Michelle Madrid, review the report's findings and recommendations…
- Episode 271 - SD v Peacemaker Case and Anjali Ranadive Interview
Hosts Eric and Glenn discuss their recent travels and fingerprint research before reviewing the homicide trial of South Dakota v. Jeremiah Peacemaker. They are joined by DNA defense expert Anjali Ranadive to analyze the fingerprint and DNA…
- Episode 270 - The TFSC Report and the Webster Case - Pt 2
In Part 2 of their discussion on the 2023 Texas Forensic Science Commission Report concerning the Joseph Webster case, Eric and Glenn examine the factors influencing a latent print examiner's conclusion and the Commission's recommendations…
- Episode 269 - The TFSC Report and the Webster Case - Pt 1
Eric and Glenn discuss the 2023 Texas Forensic Science Commission Report concerning the Joseph Webster homicide cold case. Part 1 covers background, a CODIS hit, and the re-examination of a bloody palm print initially not identified to Web…
- Episode 268 - Steve Johnson Interview
In this episode, Steve Johnson joins Eric Ray and Glenn Langenburg to discuss his work in face examination, face comparisons, and the International Association for Identification (IAI). Johnson, with experience in latent prints and forensi…
- Episode 267- Chloe George Interview - Research on Phalange Patterns
Chloe George, from New South Wales Police Force, Australia, joins the Double Loop Podcast to discuss her research on phalange pattern classification. She explains the system, first described by Marie Ploetz-Radmann in 1937, detailing 12 ge…
- Episode 266 - Andy Chapman Interview - Aussie Black Box Study
This episode features an interview with Andy Chapman of the New South Wales Police Force, who discusses a fingerprint black box error rate study. The study compared laypeople, trainees, and experts in Australia, with findings showing simil…
- Episode 265 - Dr. Bethany Growns Interview
Dr. Bethany Growns, a lecturer and psychologist, joins the Double Loop Podcast to discuss her research on visual comparison abilities, including "matchers" and "super-matchers." The conversation covers the impact of natural ability versus…
- Episode 264 - Fingerprints Proven by AI to Not Be Unique!
Eric and Glenn discuss the media mischaracterization of a Columbia University study regarding fingerprint uniqueness. They analyze the findings of the paper "Unveiling intra-person fingerprint similarity via deep contrastive learning" and…
- Episode 263 - Caitlin Rough Interview
Caitlin Rough, a Masters student at the University of Western Sydney, details her research on the interactions between sebaceous residues and blood. Her work examines how blood reacts to latent prints, observing phenomena like lipophobic r…
- Episode 262 - Teneil Hannah Interview
Teneil Hannah, a PhD candidate from the University of Technology Sydney, interviewed on the Double Loop Podcast to discuss her research on fingermark grading and quality scales. The discussion covers common scales, their importance, and po…
- Episode 261 - Fall Travel Catchup
Glenn Langenburg and Eric Ray discuss their recent travels to conferences, sharing stories from the road and highlighting presentations they observed. This episode offers a relaxed catch-up between the hosts.
- Episode 260 - Tales from the Courtroom
Glenn and Eric share surprising and unusual moments from their courtroom experiences in 2023. They invite listeners to share their own stories as well.
- Episode 259 - The 2023 IAI Conference
Eric and Glenn discuss their attendance at the 2023 International Association for Identification conference in National Harbor, MD, covering lectures, workshops, and interviews with attendees, including the popular fingerprint t-shirt at t…
- Episode 258 - Gap Science Interview
Eric Ray and Glenn Langenburg interview Erin West and Ashley Church of Gap Science about their training initiatives for forensic supervisors and management. The discussion touches on topics such as optimal reporting ratios and resources fo…
- Episode 257 - Which Forensic Discipline Is The Most Reliable?
This episode of the Double Loop Podcast features Glenn and Eric discussing forensic science reliability. They cover historical connections to fingerprints, listener questions about the most reliable forensic disciplines, and analyze studie…
- Episode 256 - Tom Busey - CSDIAI
Tom Busey joins Glenn Langenburg and Eric Ray for a panel discussion hosted by the California State Division of the IAI. They explore an alternative method for calculating fingerprint likelihood ratios, questioning the necessity of manual…
- Episode 255 - Busey Visual Evidence Paper
Eric Ray and Glenn Langenburg discuss Tom Busey's article on visual evidence in fingerprint comparison. The study analyzed how the order, diagnosticity, and clarity of features affected examiners' conclusions when presented one at a time.
- Episode 254 - NIST Latent Accuracy
This episode of the Double Loop Podcast features Glenn Langenburg and Eric Ray discussing the NIST Evaluation of Latent Friction Ridge Technology. They also touch on recent testimony about nanogram testing and compare current NIST results…
- Episode 253 - Bigger Blacker Boxes
Eric Ray and Glenn Langenburg discuss recent research on the accuracy of forensic handwriting, footwear, and bloodstain pattern comparisons, referencing studies by Austin Hicklin, et al. and Noblis. They compare this research to existing a…
- Episode 252 - Alan McNamara Interview
In Episode 252 of the Double Loop Podcast, Glenn Langenburg and Eric Ray interview Alan McNamara. McNamara details his firsthand account of the events leading to his imprisonment, covering the police interaction, trials, and appeals.
- Episode 251 - Alan McNamara Case - Part 2
Part 2 of the Alan McNamara case discussion covers the trial and expert witnesses, examining evidence details like test lifts and latent print accuracy. The episode also touches on internet comments regarding the case.
- Episode 250 - Alan McNamara Case - Part 1
Glenn Langenburg and Eric Ray discuss the Alan McNamara case from the UK, covering the details of a burglary and the police investigation. The prosecution's case relied on a single latent print despite documented issues.
- Episode 249 - IAI 2022 & Catch Up Episode
Eric and Glenn return with a catch-up episode, discussing the Great Arizona Treasure Hunt and Eric's User Conference experiences. They also share their involvement at the 2022 IAI Educational Conference, including interviews conducted at t…
- Episode 248 - Dr. Henry Swofford Interview
In this episode, Eric and Glenn interview Dr. Henry Swofford about his research on the use and validation of probabilistic tools and algorithms in the American criminal justice system. The discussion includes perspectives from various lega…
- Episode 247 - Brianne Breedlove Interview
Brianne Breedlove of Uncover Forensics joins Glenn Langenburg and Eric Ray to discuss online training in professional forensics. They cover the challenges and new benefits of the format, following a discussion on disclosure.
- Episode 246 - Stephan Cowans Case
Eric and Glenn examine the 1998 Stephan Cowans case, an example of wrongful conviction based on erroneous fingerprint evidence that was overturned by DNA testing in 2004. They discuss the case details, the subsequent review of the Boston P…
- Episode 245 - Errors and CVs and Disclosure
Eric Ray and Glenn Langenburg discuss the disclosure of forensic errors to the defense, including whether such errors belong on a CV. The episode concludes with a listener email regarding a quality control experience following an erroneous…
- Episode 244 - Hillary Moses Daluz Interview
Hillary Moses Daluz, fingerprint examiner, author, and instructor, is interviewed about her book "Courtroom Testimony for the Fingerprint Examiner." The discussion covers challenges in courtroom testimony for examiners and maintaining posi…
- Episode 243 - New Years Grab Bag
In the first episode of 2022, Eric Ray and Glenn Langenburg cover emails regarding a new conclusion proposal, photography setups using transmitted light, and the requirement for agencies to include quantitative or qualitative statements in…
- Episode 242 - Review of ASB Documents 2021
The Double Loop Podcast episode discusses Thanksgiving traditions and reviews two proposed ASB standards: ASB 013 for Friction Ridge Examination Conclusions and ASB 144 for Verification Component of Friction Ridge Examination. The hosts co…