Double Loop Podcast

Episode 286 - IAI 2025 Review

13 Dec 2025

Contributed by Lukas

Eric Ray and Glenn Langenburg talk about their week in Orlando at the 2025 IAI Educational Conference. Hear about Quality Metrics, limited examination...

Episode 286 - Forensic Science Ireland Interview

30 Sep 2025

Contributed by Lukas

In this episode Eric poses to Glenn a Mandela effect question concerning household cleaning products.  After that, the guys celebrate the 4th of Jul...

Episode 285 - Michael Whyte Interview - Latent to Latent Comparisons

12 Aug 2025

Contributed by Lukas

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, Mic...

Episode 284 - Black Box '22 - Part 2 (with Brendan Max)

28 Jul 2025

Contributed by Lukas

In this episode, Eric stumps Glenn with a geography based Mandela Effect question. Then the guys welcome their guest commentator, Brendan Max, Public...

Episode 283 - DNA & Patterns

26 May 2025

Contributed by Lukas

Glenn Langenburg and Eric Ray review two articles from Cell that focus on the genetic basis for ridge development and pattern formation. 'The developm...

Episode 282 - Noblis-FBI Black Box 2 Fingerprint Study

10 May 2025

Contributed by Lukas

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 reg...

Episode 281 Kasey Wertheim Tribute

06 Apr 2025

Contributed by Lukas

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 ...

Episode 280 - Pat Wertheim Tribute

21 Mar 2025

Contributed by Lukas

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 reme...

Episode 279 - Simultaneous Impressions

16 Mar 2025

Contributed by Lukas

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 n...

Episode 278 - Aussie Paper on Examiner Disagreements

03 Mar 2025

Contributed by Lukas

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 cat...

Episode 277 - Sarah Chu Interview

14 Jan 2025

Contributed by Lukas

Glenn and Eric interview Sarah Chu, director of policy and reform with the Perlmutter Center for Legal Justice's (PCLJ) forensic science policy initia...

Episode 276 - History Episode - Stories of the Forefathers

09 Dec 2024

Contributed by Lukas

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 “...

Episode 275 - 2024 IAI Conference: The Reno Recap

01 Nov 2024

Contributed by Lukas

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”,...

Episode 274 - NIST Inconclusive Paper

01 Sep 2024

Contributed by Lukas

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. T...

Episode 273 - Angela Hilliard Interview - Erroneous Exclusions

16 Jul 2024

Contributed by Lukas

Glenn and Eric are joined by Angela Hilliard to discuss her experiences with a cold case from the Pacific Northwest. Genetic genealogy provided a susp...

Episode 272 - DNA and Human Factors Expert Working Group Report

30 Jun 2024

Contributed by Lukas

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...

Episode 271 - SD v Peacemaker Case and Anjali Ranadive Interview

06 May 2024

Contributed by Lukas

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 ...

Episode 270 - The TFSC Report and the Webster Case - Pt 2

21 Apr 2024

Contributed by Lukas

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 disc...

Episode 269 - The TFSC Report and the Webster Case - Pt 1

08 Apr 2024

Contributed by Lukas

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...

Episode 268 - Steve Johnson Interview

21 Mar 2024

Contributed by Lukas

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 ...

Episode 267- Chloe George Interview - Research on Phalange Patterns

09 Mar 2024

Contributed by Lukas

Eric and Glenn host another guest from Australia in today’s episode. After another round of Where in the Whorld and a few stories from Eric’s chi...

Episode 266 - Andy Chapman Interview - Aussie Black Box Study

17 Feb 2024

Contributed by Lukas

In this post-New Year’s Eve 2023-2024 episode, the guys start by discussing their New Year’s Eve and play another round of Where in the Whorld. T...

Episode 265 - Dr. Bethany Growns Interview

02 Feb 2024

Contributed by Lukas

Glenn and Eric start by talking about their Christmas plans, followed by a game of “Where in the Whorld”. They then welcome their guest, Dr. Beth...

Episode 264 - Fingerprints Proven by AI to Not Be Unique!

20 Jan 2024

Contributed by Lukas

Eric and Glenn respond to the recent allegations that a computer science undergraduate at Columbia University, using Artificial Intelligence, has “p...

Episode 263 - Caitlin Rough Interview

12 Jan 2024

Contributed by Lukas

In this episode, Eric and Glenn interview Caitlin Rough, a Masters student at the University of Western Sydney. Glenn saw Caitlin present at the IAFS...

Episode 262 - Teneil Hannah Interview

29 Dec 2023

Contributed by Lukas

Eric and Glenn discuss their holiday parties and preparations, play another round of "Where in the Whorld?", and then interview a guest all the way fr...

Episode 261 - Fall Travel Catchup

19 Dec 2023

Contributed by Lukas

Glenn Langenburg and Eric Ray spent the past few months traveling to conferences far and wide. This episode they catch up with each other on recent tr...

Episode 260 - Tales from the Courtroom

25 Nov 2023

Contributed by Lukas

Eric and Glenn return with a super-sized episode where they trade courtroom stories. Glenn had two cases in 2023 where the judges and decisions were ...

Episode 259 - The 2023 IAI Conference

22 Sep 2023

Contributed by Lukas

Eric and Glenn share their adventures at the 2023 International Association for Identification conference held in August in National Harbor, MD in the...

Episode 258 - Gap Science Interview

15 Sep 2023

Contributed by Lukas

Eric Ray and Glenn Langenburg are at the 2023 IAI conference in National Harbor, MD with Erin West and Ashley Church of Gap Science. They've developed...

Episode 257 - Which Forensic Discipline Is The Most Reliable?

13 Aug 2023

Contributed by Lukas

To start the episode, Glenn tells Eric a story relating to Edmond Locard and Galdino Ramos, a doctor with an interesting connection to the history of ...

Episode 256 - Tom Busey - CSDIAI

20 Jul 2023

Contributed by Lukas

Glenn Langenburg and Eric Ray bring the podcast to the California State Division of the IAI. Tom Busey joins the panel, and they discuss one of Tom's ...

Episode 255 - Busey Visual Evidence Paper

12 Jun 2023

Contributed by Lukas

Eric Ray and Glenn Langenburg discuss the recent article from Tom Busey - Tracking the growth of visual evidence in fingerprint comparison tasks. Exam...

Episode 254 - NIST Latent Accuracy

03 Apr 2023

Contributed by Lukas

Glenn Langenburg and Eric Ray eventually discuss the results of the recent NIST Evaluation of Latent Friction Ridge Technology. But first there are a ...

Episode 253 - Bigger Blacker Boxes

21 Feb 2023

Contributed by Lukas

Eric Ray and Glenn Langenburg tackle three new Black Box / Accuracy studies from Austin Hicklin, et al and Noblis. Results from research into the accu...

Episode 252 - Alan McNamara Interview

08 Feb 2023

Contributed by Lukas

Glenn Langenburg and Eric Ray are joined by Alan McNamara to continue discussing the case that sent him to jail. Alan shares his story from the day th...

Episode 251 - Alan McNamara Case - Part 2

14 Jan 2023

Contributed by Lukas

Eric Ray and Glenn Langenburg continue their discussion of the Alan McNamara case from the UK. This time they start with the trial and then go through...

Episode 250 - Alan McNamara Case - Part 1

06 Jan 2023

Contributed by Lukas

Glenn Langenburg and Eric Ray discuss the case of Alan McNamara from the UK. In this episode we cover the details of the burglary and how the police f...

Episode 249 - IAI 2022 & Catch Up Episode

07 Dec 2022

Contributed by Lukas

Eric and Glenn return from a hiatus to have a more relaxed catch-up episode. They share an adventure or two including the great Arizona Treasure Hunt...

Episode 248 - Dr. Henry Swofford Interview

11 Aug 2022

Contributed by Lukas

Eric and Glenn interview returning guest, and newly minted PhD, Dr. Henry Swofford on his recent paper, with co-author Prof. Christophe Champod: “Pr...

Episode 247 - Brianne Breedlove Interview

29 Jun 2022

Contributed by Lukas

Glenn Langenburg and Eric Ray sit down with Brianne Breedlove from Uncover Forensics to discuss online training and how things have changed in profess...

Episode 246 - Stephan Cowans Case

07 May 2022

Contributed by Lukas

Today, Eric and Glenn FINALLY review the Stephan Cowans case, a case of an erroneous identification from Boston where a fingerprint identification was...

Episode 245 - Errors and CVs and Disclosure

31 Mar 2022

Contributed by Lukas

Eric Ray and Glenn Langenburg go round and around on the topic of how to disclose errors to defense. Should your errors be listed in your CV? Should t...

Episode 244 - Hillary Moses Daluz Interview

05 Feb 2022

Contributed by Lukas

In this episode, the guys interview fingerprint examiner, multi-book author, and instructor, Hillary Moses Daluz . Hillary discusses her new book "Co...

Episode 243 - New Years Grab Bag

31 Jan 2022

Contributed by Lukas

Eric Ray and Glenn Langenburg catch up on a mix bag of topics in the first episode of 2022. Emails on the new conclusion proposal, setups for photogra...

Episode 242 - Review of ASB Documents 2021

27 Dec 2021

Contributed by Lukas

In this episode, the guys talk about Thanksgiving: Eric’s amazing food preparation and Glenn’s travel to Canada to teach. Eric also gives a plug ...

Episode 241 - Blind Proficiency Testing Paper

01 Dec 2021

Contributed by Lukas

Eric Ray and Glenn Langenburg discuss the recent paper on Blind Proficiency Testing from the Houston Forensic Science Center: "Latent print quality in...

Episode 240 - Todd Weller returns to discuss inconclusives

21 Oct 2021

Contributed by Lukas

The long awaited/dreaded return of the “Dad Joke Intro”! In this episode, Todd Weller (firearms expert) returns to the show to talk to Eric and G...

Episode 239 - 2021 IAI Conference

27 Sep 2021

Contributed by Lukas

Return with Glenn and Eric to the IAI Conference in Nashville, TN. The guys are joined by Josh Connelly, Kurt Aebersold, JP Rodriguez, and Claudine Ca...

Episode 238 - Dror and Scurich Article

06 Jul 2021

Contributed by Lukas

Glenn Langenburg and Eric Ray review the 2020 article from Itiel Dror and Nicholas Scurich. "(Mis)use of scientific measurements in forensic science" ...

Episode 237 - Testifying After an Error

25 Apr 2021

Contributed by Lukas

Glenn Langenburg and Eric Ray discuss how to testify in court after an error occurs. Examiners nervous about upcoming testimony can find tips whether ...

Episode 236 - Mindset Paper (Palms Part Deux!)

25 Mar 2021

Contributed by Lukas

In this episode, the guys return for Round 2 with Dr. Heidi Eldridge and Prof. Christophe Champod. This time, they discuss the second paper arising f...

Episode 235 - Todd Weller Interview

12 Mar 2021

Contributed by Lukas

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 E...

Episode 234 - Palm Print Black Box Study

26 Feb 2021

Contributed by Lukas

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...

Episode 233 - GYRO Accuracy Paper

16 Feb 2021

Contributed by Lukas

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 Con...

Episode 232 - Differing Conclusions Article

06 Jan 2021

Contributed by Lukas

Glenn Langenburg and Eric Ray review the newest article from Austin Hicklin, Bradford Ulery, Madeline Ausdemore, and JoAnn Buscaglia. Why do latent fi...

Episode 231 - Conclusion Scales Article

23 Nov 2020

Contributed by Lukas

After some Halloween talk, Eric and Glenn discuss this episode’s research article: “The Utility of Expanded Conclusion Scales During Latent Print ...

Episode 230 - Fingerprint Error Rate in Close Non-Matches

28 Oct 2020

Contributed by Lukas

In this Halloween episode, Eric and Glenn discuss a new paper published by Koehler and Liu titled “Fingerprint error rate on close non-matches” (J...

Episode 229 - Bob Garrett

13 Oct 2020

Contributed by Lukas

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 ...

Episode 228 - Knuckle-Crease Daubert Hearing

16 Sep 2020

Contributed by Lukas

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 tri...

Episode 227 - NY Firearms Case

02 Sep 2020

Contributed by Lukas

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 e...

Episode 226 - Best Latent Print Books

20 Jul 2020

Contributed by Lukas

Glenn Langenburg and Eric Ray were recently asked which latent print books they recommend the most. This episode they talk through the absolute creme ...

Episode 225 - The Most Dangerous Animal of All Documentary

01 Jul 2020

Contributed by Lukas

This week, the guys review and share their reactions to the documentary “The Most Dangerous Animal of All” (produced by Campfire Productions and a...

Episode 224 - Forensics in the New Normal

16 Jun 2020

Contributed by Lukas

Glenn Langenburg and Eric Ray take a break from normal interviews and research reviews to host a laid-back happy hour discussion on how things have be...

Episode 215 - Aging Latent Prints

02 Jun 2020

Contributed by Lukas

Eric and Glenn wrap up their “activity level series” by discussing two articles (Girod, et al. 2016; and Hinners, et al. 2020) which propose deter...

Episode 223 - Luke Ryan Interview - Mass Drug Scandal Part 3

24 May 2020

Contributed by Lukas

In the final and third part of the series on the Massachusetts drug scandals and Netflix documentary, we interview Luke Ryan, the defense attorney fea...

Episode 222 - How to Fix a Drug Scandal Documentary - Part 2

06 May 2020

Contributed by Lukas

Eric and Glenn finish out their discussion of the new Netflix documentary “How to Fix a Drug Scandal” (2020). In this episode we switch our focus ...

Episode 217 - Forensic Movie Recommendations during COVID-19

29 Apr 2020

Contributed by Lukas

In the wake of COVID-19 and so many of us staying at home, we decided as an April Fools’ Episode to make a list of movies that we enjoy and feature ...

Episode 221 - How to Fix a Drug Scandal Documentary - Part 1

27 Apr 2020

Contributed by Lukas

In the first of two episodes, Glenn and Eric discuss Netflix’s “How to Fix a Drug Scandal” (2020), covering the actions and consequences of two ...

Episode 220 - Blind QC Research at HFSC

20 Apr 2020

Contributed by Lukas

In this episode, Eric and Glenn start the show discussing a few kind emails and reviews of this podcast. They also talk about a weekly social event o...

Episode 219 - David Camm Case - Part 2

15 Apr 2020

Contributed by Lukas

The case against David Camm is about to be turned on its head. Eric Ray and Glenn Langenburg continue the story with a second and third trial and the ...

Episode 218 - David Camm Case - Part 1

07 Apr 2020

Contributed by Lukas

In this multi-part series on the Indiana v. David Camm case, Eric and Glenn review the evidence over multiple episodes. In this first episode they re...

Episode 216 - OSAC Update and Travel Stories

19 Mar 2020

Contributed by Lukas

Glenn Langenburg returns from international travels (just in time) and brings stories from distant lands of England and Minnesota. As the discussion t...

Episode 214 - Simon Bunter Interview

24 Feb 2020

Contributed by Lukas

Glenn Langenburg is joined by Simon Bunter from Keith Borer Consultants to discuss a number of cases where activity level propositions were key factor...

Episode 213 - Anouk de Ronde Interview

04 Feb 2020

Contributed by Lukas

Eric Ray and Glenn Langenburg are joined by Anouk de Ronde from the Amsterdam University of Applied Sciences to continue the discussion on activity le...

Episode 212 - Activity Level

15 Jan 2020

Contributed by Lukas

In this episode Glenn and Eric dig into ‘activity level propositions’, which will start a series of episodes that takes a deep dive into this topi...

Episode 211 - OSAC & ASB Update

08 Jan 2020

Contributed by Lukas

Eric Ray and Glenn Langenburg get passionate about policies. Stirred up about standards. PO'd about SDO's. After a quick refresher on how NIST, OSAC, ...

Episode 210 - Brendan Max Interview

15 Dec 2019

Contributed by Lukas

In this episode, Glenn and Eric interview Brendan Max, Chief of the Cook County Public Defender Forensic Science Unit in Illinois. They discuss his n...

Episode 209 - Friction Ridge Process Map

09 Dec 2019

Contributed by Lukas

Eric Ray and Glenn Langenburg talk through the latest document out of the OSAC Friction Ridge Subcommttee. Last month they released an updated, and de...

Episode 208 - Review of Conflict Resolution Paper (Montani, et al.)

29 Nov 2019

Contributed by Lukas

This episode, the guys review and discuss a paper about resolving conflict resolution from Montani, et al. titled “Resolving differing expert opinio...

Episode 207 - AC Brogdon Interview

16 Nov 2019

Contributed by Lukas

Eric Ray starts the show sharing some big news with Glenn Langenburg and the listeners. The guys are then joined by AC Brogdon, president of the Calif...

Episode 206 - OSAC FRS Standards for Conclusions

25 Oct 2019

Contributed by Lukas

In this episode, Eric and Glenn tackle the 2018 proposed OSAC Friction Ridge Subcommittee (FRS) Standards for Conclusions. They review the entire doc...

Episode 205 - PNW Conference Panel

17 Oct 2019

Contributed by Lukas

Glenn Langenburg leads a panel discussion (with Eric Ray joining via phone) at the Pacific Northwest Division of the IAI / Northwest Association of Fo...

Episode 204 - 2019 IAI Conference

23 Sep 2019

Contributed by Lukas

Join Glenn Langenburg and Eric Ray in Reno, NV for the 2019 International Association for Identification conference. We are joined by Becca Coutant, C...

Episode 203 - FBI Persistency Paper

16 Sep 2019

Contributed by Lukas

Eric Ray and Glenn Langenburg review a new paper that's been long in the making. "The permanence of friction ridge skin and persistence of friction ri...

Episode 202 - Idaho Interviews

21 Aug 2019

Contributed by Lukas

Eric Ray was recently teaching in Idaho (the ID state) and had the opportunity to sit down with Nick Craven, Katlyn Shelar, Whitney Betzel, and Tara K...

Episode 201 - Gaze Detection Article

25 Jul 2019

Contributed by Lukas

Eric Ray and Glenn Langenburg discuss the new article from Austin Hicklin, Brad Ulery, Tom Busey, and company researching latent print examiners with ...

Episode 200 - Michael Whyte Interview

11 Jul 2019

Contributed by Lukas

EPISODE 200!!! - Eric Ray and Glenn Langenburg celebrate the big number 200 with an overseas interview with Australian latent print examiner and frien...

Episode 199 - Brandon Garrett Interview

11 May 2019

Contributed by Lukas

Eric and Glenn return from a couple weeks off of crazy travels with a few stories from the road including a "Men Who Love My Little Pony" ("Bronies") ...

Episode 198 - Archie Williams Case

01 Apr 2019

Contributed by Lukas

Eric Ray and Glenn Langenburg start the show talking about some exciting new classes that they have developed. Then they discuss which is more correc...

Episode 197 - Review of Miami-Dade Error Rates

18 Mar 2019

Contributed by Lukas

Glenn and Eric start with a brief chat about ethics and the recent JFI letter regarding testing and studies involving human subjects. They then jump i...

Episode 196 - Gianni Ribeiro Article and Interview

07 Mar 2019

Contributed by Lukas

Eric Ray and Glenn Langenburg discuss post-Laura Interview thoughts after last episode's "lay person" interview. They tie in a new paper surveying mo...

Episode 195 - Laura Keck Interview

22 Feb 2019

Contributed by Lukas

Glenn Langenburg and Eric Ray interview friend-of-the-show, Laura Keck, and dive deep into how forensic evidence is interpreted by a lay person. Does ...

Episode 194 - Melting Pot of Topics

14 Feb 2019

Contributed by Lukas

Eric Ray shares some big news and then shares a story about the dictionary. Glenn Langenburg brings another Super Fan into the fold as the Double Loop...

Episode 193 - Fingerprints for Investigative Leads

29 Jan 2019

Contributed by Lukas

After arguing about the Mandela Effect, Glenn and Eric catch up on some email and discuss ANAB AR3125 7.8.1.2.2 and how this impacts reporting conclus...

Episode 192 - Mark Stolorow Interview

22 Jan 2019

Contributed by Lukas

Glenn Langenburg and Eric Ray are proud to be joined by Mark Stolorow. Before his years guiding the creation of the OSAC and his days with NIST, he ha...

Episode 191 - Christophe Champod Interview

13 Jan 2019

Contributed by Lukas

Eric Ray and Glenn Langenburg are joined for another episode discussing statistics and probabilities by Professor Christophe Champod from the Universi...

Episode 190 - Gianni Ribeiro Interview (and OSAC)

30 Dec 2018

Contributed by Lukas

Eric Ray and Glenn Langenburg interview Australian researcher Gianni Ribeiro at the December 2018 OSAC meeting in Phoenix, AZ. Gianni tells the guys a...

Episode 189 - Henry Swofford Interview

22 Dec 2018

Contributed by Lukas

Glenn Langenburg and Eric Ray are joined in-person by Henry Swofford as they discuss his career with the Army Crime Lab and the development of FRStat,...

Episode 188 - Cedric Neumann Interview

10 Dec 2018

Contributed by Lukas

Glenn Langenburg and Eric Ray are joined by Cedric Neumann to discuss all things statistical models, probabilities, likelihood ratios, Bayes factors, ...