Eric and Glenn wrap up their “activity level series” by discussing two articles (Girod, et al. 2016; and Hinners, et al. 2020) which propose determination of aging of latent fingerprint residue. The techniques use instrumental techniques to identify breakdown products of various fatty components in latent print residue, and use these results to classify whether a latent print is a couple of days old, or older (up to a week or month old depending on the paper). This is a nice finale to the series...
Jun 02, 2020•55 min
In the final and third part of the series on the Massachusetts drug scandals and Netflix documentary, we interview Luke Ryan, the defense attorney featured in the documentary and who represented several of the clients affected by the scandal. Luke described how and why he fought to uncover the truth that was being swept under the rug by the Attorney General’s office. We also discussed a number of other issues that were not shown in the documentary, including deliberate and willful collusion by t...
May 24, 2020•1 hr 56 min
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 on the dry-labbing of drug tests by Annie Dookhan, and how long it took for those tests and convictions from those test to finally get tossed. The episode concludes with the story of Luke Ryan and his crusade to finally find the evidence that clearly demonstrated that Sonja Farak had been using drugs for years and not just months. Join Glenn and Eric o...
May 06, 2020•1 hr 15 min
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 an aspect of forensic science. Eric and Glenn run down our top 10 movies (with two “so bad, they’re good” recommendations) and a few honorable mentions for you to consider while deciding what movies or shows to binge. We also alert listeners at the end to a call for research, regarding a new “verification practices” survey that you can take.
Apr 29, 2020•1 hr 20 min
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 Massachusetts drug chemists. In this episode, they mostly focus on the Sonja Farak aspect, who was a drug chemist, addicted to drugs and stealing drugs from her standards cabinet and evidence. The guys discuss the issue of ‘random drug screenings’ of crime lab employees and the lack of other various controls in the U.S. The lack of controls can allow cir...
Apr 27, 2020•1 hr 5 min
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 online—an online Happy Hour on Discord for Latent Print Examiners and friends of the show. In the main segment, the guys review Hundl et al. (2019) “Implementation of a Blind Quality Control Program in a Forensic Laboratory” in the Journal of Forensic Sciences. This research paper discusses the results of introducing over 140 realistic ground truth c...
Apr 20, 2020•1 hr 5 min
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 introduction of a mountain of evidence against a new suspect. The episode concludes with an in-depth discussion on the importance of considering multiple scenarios in bloodstain pattern and all forensic disciplines. It all ties back to our previous discussions of activity level propositions.
Apr 15, 2020•1 hr 11 min
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 review the evidence of the Prosecution and the first trial. There is discussion regarding latent print evidence, DNA evidence, crime scene reconstruction, medical examiner findings, and blood stain pattern evidence. The blood stain evidence is fairly critical in placing David Camm at the scene of a triple homicide (his wife and two young children).
Apr 07, 2020•1 hr 4 min
Glenn Langenburg returns from international travels (just in time) and brings stories from distant lands of England and Minnesota. As the discussion turns to conclusions, Eric Ray brings an update from the OSAC Friction Ridge Subcommittee. Check the NIST OSAC website in the near future for updated versions of Friction Ridge Subcommittee proposed standards.
Mar 19, 2020•1 hr 7 min
Glenn Langenburg is joined by Simon Bunter from Keith Borer Consultants to discuss a number of cases where activity level propositions were key factors. Can a print survive after the surface is cleaned? What if the surface is painted over? Simon tells some amazing stories that should make every latent print examiner question the timeline of when a latent print was left on a surface.
Feb 24, 2020•1 hr 11 min
Eric Ray and Glenn Langenburg are joined by Anouk de Ronde from the Amsterdam University of Applied Sciences to continue the discussion on activity level propositions. Anouk has published on how to construct a logical framework for considering all the information in a latent print to assist in establishing probabilities for competing hypotheses. Did he climb the railing or just lean against it? Was the pillowcase changed or was the pillow pressed down? Just like you wouldn't reach an Identificat...
Feb 04, 2020•1 hr 5 min
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 topic. We lay the groundwork for the topic by discussing fundamental forensic science papers, such as Evett, et al. “The impact of the principles of evidence interpretation on the structure and content of statements” (Science & Justice, 2000) and other works by Cook and Jackson. We highlight the need for formal declaration of propositions regarding ‘so...
Jan 15, 2020•1 hr 6 min
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, AAFS, and ASB fit together in the Standards Development process, Eric and Glenn give an update on the draft standards for latent prints. Where are the standards that we've been waiting for? There was a recent meeting the Friction Ridge group with ASB, and things did not go well for those of us that would like to see the process move forward. While ...
Jan 08, 2020•1 hr 18 min
In this episode, Glenn and Eric interview Brendan Max, Chief of the Cook County Public Defender Forensic Science Unit in Illinois. They discuss his new article “Assessing Latent Print Proficiency Tests: Lofty Aims, Straightforward Samples, and the Implications of Non-Expert Performance” (Max, Cavise, and Gutierrez in JFI 2019;69(3)). Brendan shares his views on proficiency tests: are they meaningful? What about verifications in proficiency testing? What does it mean to ‘fail’ a test? How do lawy...
Dec 15, 2019•1 hr 17 min
Eric Ray and Glenn Langenburg talk through the latest document out of the OSAC Friction Ridge Subcommttee. Last month they released an updated, and detailed, process map for friction ridge examinations. Follow along by downloading the pdf from the OSAC FRS website, https://www.nist.gov/topics/forensic-science/friction-ridge-subcommittee. Eric and Glenn are also happy to announce the Double Loop Podcast merch store. Go to doublelooppodcast.com, click on the Store tab, and help support the show.
Dec 09, 2019•1 hr 7 min
This episode, the guys review and discuss a paper about resolving conflict resolution from Montani, et al. titled “Resolving differing expert opinions” (Science & Justice 2019). They explore the nuances of the recommendations from the paper and Glenn applied the principles to a recent case and conflict resolution he experienced. But before getting into the paper, Eric gushes some more about his new job and discusses a recent podcast that he guested on (“Stinker Madness”). Glenn also discusse...
Nov 29, 2019•1 hr 14 min
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 California State Division of the IAI for an discussion on the importance of the work that we do. AC shares some stories of his early life, and how those experiences shaped the person that he is and how that continues to inspire and motivate him. It's vitally important for examiners and investigators to remember the victims as they do their work and that...
Nov 16, 2019•58 min
In this episode, Eric and Glenn tackle the 2018 proposed OSAC Friction Ridge Subcommittee (FRS) Standards for Conclusions. They review the entire document and provide the definitions for 5 conclusions: identification, exclusion, inconclusive, and support for same/different sources. They give their thoughts and reactions to these terms and give examples of when they might apply. Glenn discusses an upcoming jury trial where he will be using these terms and how they appear in his reports. Bonus: an...
Oct 25, 2019•1 hr 27 min
Glenn Langenburg leads a panel discussion (with Eric Ray joining via phone) at the Pacific Northwest Division of the IAI / Northwest Association of Forensic Scientists Joint Conference with guests and Janis Puracal from the Forensic Justice Project and Carey Hall. The panel discussion explores the Janis's history with exonerations, innocence, justice reform, and forensic science and the challenges that face those that have been erroneously convicted. The conversation also explores the challenges...
Oct 17, 2019•1 hr 26 min
Join Glenn Langenburg and Eric Ray in Reno, NV for the 2019 International Association for Identification conference. We are joined by Becca Coutant, Carey Hall, Nicole Praska, Claudine Carter Pereira, and Jason Jardine and cover a number of topics including limited examinations, defense attorney perspectives, conclusion terminology, blood prints, management, and stats. There's even a little story of Glenn losing his cool and an out-take for the blooper reel. The conference was fantastic, and big...
Sep 23, 2019•48 min
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 ridge skin and impressions: A comprehensive review and new results" by Monson, et al. was recently published in Forensic Science International. The paper details the persistence and permanence of 1st, 2nd, and 3rd level detail over multiple years. There are important takeaways from the paper although it isn't quite the level of the FBI/Noblis papers....
Sep 16, 2019•1 hr 8 min
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 Koho and talk with them about topics ranging from latent print exclusions, AFIS candidate lists, and the future of statistical models. Glenn Langenburg then joins Eric to continue the discussion with some follow-up points and continuing the conversation further into Exclusion policies and requirements, the nature of risk, and a preview on how to use...
Aug 21, 2019•1 hr 34 min
Eric Ray and Glenn Langenburg discuss the new article from Austin Hicklin, Brad Ulery, Tom Busey, and company researching latent print examiners with eye tracking equipment. Gaze behavior and cognitive states during fingerprint target group localization was published in Cognitive Research and examines what we look at and how context plays a huge part in this process. Download the paper online and follow along as we explore a great new paper.
Jul 25, 2019•1 hr 7 min
EPISODE 200!!! - Eric Ray and Glenn Langenburg celebrate the big number 200 with an overseas interview with Australian latent print examiner and friend of the show, Michael Whyte. The guys talk forensics down under, some of the travels, teaching, and technology that Michael is involved with and announce DoubleLoopPodcast.com. Check it out, and let us know how we can make it even better.
Jul 11, 2019•1 hr 11 min
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") cosplay conference. In this episode, the guys sit down for a fantastic interview with Duke Law Professor Brandon Garrett to discuss his and colleagues' recent juror study. The most recent paper provides fingerprint proficiency test results to mock jurors to see how this information may impact their decision making and how reliable they believe fing...
May 11, 2019•1 hr 12 min
Eric Ray and Glenn Langenburg start the show talking about some exciting new classes that they have developed. Then they discuss which is more correct: 2009 "NRC" Report or "NAS" Report. Finally, they describe the available facts in the recent Archie Williams Innocence Project exoneration case. He was freed after 36 years in prison for rape based on eyewitness identifications, but an AFIS hit now implicates another person.
Apr 01, 2019•1 hr 2 min
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 into the main discussion on the "Review of Several False Positive Error Rate Estimates for Latent Fingerprint Examination Proposed Based on the 2014 Maimi-Dade Police Department Study" by Madeline Ausdemore, Jessie Hendricks, and Cedric Neumann. The review found that the data best fit a model of two error rates: one for when the true match is not pr...
Mar 18, 2019•1 hr 15 min
Eric Ray and Glenn Langenburg discuss post-Laura Interview thoughts after last episode's "lay person" interview. They tie in a new paper surveying mock-jurors, published by Gianni Ribeiro from Australia. Later, Gianni calls in from Oz to discuss her research. Oh, and Eric and Glenn both come up with genius ideas this episode.
Mar 07, 2019•1 hr 28 min
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 one fingerprint identification vs. 13 fingerprint identifications make a difference? What if the prints were on an inner drug baggie vs. an outer drug baggie? What is an acceptable error rate for latent prints or DNA? What if there is no other forensic evidence? Laura's perspective as a lay person (but with knowledge and interest in forensic scienc...
Feb 22, 2019•1 hr 13 min
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 Podcast website starts to come together and some new research from Australia ( https://www.youtube.com/watch?v=7dG6Rw8_KLg ). They both then revisit the discussion on investigative leads. It's important to understand the distinction between reporting AFIS hits as preliminary without verification and a true "investigative lead" where there are only...
Feb 14, 2019•52 min
