Double Loop Podcast

Eric Ray and Glenn Langenburg discuss the recent article from Tom Busey - Tracking the growth of visual evidence in fingerprint comparison tasks. Examiners were shown features one at a time and asked to reach conclusions after each one. The study measured differences from the order of features revealed, their diagnosticity, and their clarity.

Glenn Langenburg and Eric Ray eventually discuss the results of the recent NIST Evaluation of Latent Friction Ridge Technology. But first there are a couple of detours. Glenn discusses recent testimony regarding questionable nanogram testing for the presence of drugs. Eric talks about the Cousins By Blood podcast and his involvement in that case. Once the discussion returns to NIST testing, the guys review the differences between the most recent tests and the previous round in 2012. Follow along with the discussion by viewing the results at: https://pages.nist.gov/elft/elft_1_x/results/

Eric Ray and Glenn Langenburg tackle three new Black Box / Accuracy studies from Austin Hicklin, et al and Noblis. Results from research into the accuracy of forensic handwriting comparison, footwear comparison, and bloodstain pattern comparison have been recently published. The guys break down the nuances of this research and how its similar and different from the latent fingerprint and palm print black box accuracy studies.

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 the police first knocked on his door through the trials and appellate hearings. His first-hand account of this miscarriage of justice is an eye-opener for forensic scientists and for everyone with an interest in the criminal justice system anywhere in the world. Images and reports from this case are available at patreon.com/DoubleLoopPodcast.

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 many of the expert witnesses that got involved in this case. Why do all the test lifts from the jewelry box have a wood grain in the background, but there is no grain in the evidence lift? Does the hook or Chinese character shape mean anything? How important is testimony about the homeowner's cleaning schedule? Can latent prints survive regular cleanings? Should there be questions about the accuracy of the latent print identifications to the homeowner? Eric then reads some of the internet comments that were made when the Alan McNamara case was first featured on the BBC's Panorama. Join us again on the next episode where we interview Alan McNamara.

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 focused on Alan McNamara. Despite many issues in the latent print evidence, charges moved forward. The prosecution's entire case was based on a single latent print with questionable documentation.

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 that they participated in. Eric shares some experiences from the User Conference he worked. And finally the guys talk about the Double Loop Podcast booth experience at the 2022 Omaha IAI Educational Conference. They play a bunch of clips and recordings from our “Correspondent” Rebecca Coutant who was running the booth and playing “(Wo)Man on the Street” to get some attendee perspectives.

Eric and Glenn interview returning guest, and newly minted PhD, Dr. Henry Swofford on his recent paper, with co-author Prof. Christophe Champod: “Probabilistic reporting and algorithms in forensic science: Stakeholder perspectives within the American criminal justice system” (For Sci Intl Synergy 2020; https://doi.org/10.1016/j.fsisyn.2022.100220). The new article discusses interview responses from judges, prosecutors, defense attorneys, scholars, and forensic laboratory managers regarding their perspective on how to validate, implement, litigate, and communicate probabilistic tools and algorithms in American courts. They discuss different quotes and perspectives from the paper and relate that to their own experiences and observations. Henry also makes an important reference to a companion paper, that provides concrete recommendations and a strategy towards implementation by practitioners: “Implementation of algorithms in pattern and impression evidence: A responsible and practical roadmap” (FSI Synergy 2021; https://doi.org/10.1016/j.fsisyn.2021.100142).

Glenn Langenburg and Eric Ray sit down with Brianne Breedlove from Uncover Forensics to discuss online training and how things have changed in professional forensic training over the past few years. What are the challenges in this new format? What are the benefits that we could never do before? At the beginning Eric and Glenn finish off last episode's discussion on disclosure. Make sure to check out the new shirts and other merchandise at DoubleLoopPodcast.com.

Today, Eric and Glenn FINALLY review the Stephan Cowans case, a case of an erroneous identification from Boston where a fingerprint identification was critical evidence used to convict Cowans in 1998. This case is one of the few Innocence Project cases where there was an erroneous fingerprint identification but DNA was able to exonerate Cowans in 2004 (and the true source of the latent print was later identified). Eric and Glenn go through the major elements of the case and the subsequent review of the Boston Police Department Latent Print Unit by an external consultant. At the end, they discuss the critical improvements and advancements made in the wake of the error and why these cases are still important today to review and remember.