Double Loop Podcast

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.

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.

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 Identification without looking at each individual minutiae, this framework allows for examination of each data point before making a conclusion on the likelihood of different activity level propositions.

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 ‘source’, ‘activity’, and ‘crime (offense)’ levels. Lastly, we discuss aging (time since deposition) of latent prints and the dangers of these statements based on a visual exam alone. We reference Girod, Ramotowski, et al. “Fingermark age determinations: Legal considerations, review of the literature, and practical propositions” (For Sci Intl, 2016) for important points here. Also Glenn has some news at the beginning of the show to share with Eric regarding DNA.

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 you're waiting for things to move forward, don't forget to check out the Double Loop Podcast merch store at www.doublelooppodcast.com

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 lawyers and judges view proficiency tests? He describes his basic strategy for litigating forensic evidence and explains why the research in the field of latent prints is so critical. Pay attention towards the end: Eric legitimately stumps Glenn with a great question!

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.

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 discusses some draft documents available through OSAC and some upcoming changes to OSAC.

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 it's not just another day at the office for those directly affected by the crime. Part of maintaining that motivation is to recognize that this job comes with unique stress, especially for those collecting and documenting evidence at the crmie scene. Employee assistance programs are available through most agencies to help all of us deal with the terrible things that we can exposed to every day.

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 unexpected discussion of Downton Abbey! Upcoming classes mentioned at the end. Note: this episode has premium content for our Patreon Supporters.