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 to explore what the realities and limitations of aging latent prints entails, rather than relying on visual inspection and qualified “consistent with” statements that previous episodes revealed could be misleading or just plain wrong.  Glenn also starts the show by relaying a little bit of his experience joining the new NIST/NIJ Human Factors Expert Working Group on DNA mixture interpretation.

Episode 215 - Aging Latent Prints

Whether you're a practicing Latent Print Examiner or you're interested in forensics and true crime, the Double Loop Podcast is a weekly show featuring Glenn Langenburg and Eric Ray discussing latent print topics, current events in forensic science, the newest research articles, interesting guests, and analysis of notable cases from a forensic scientist perspective.

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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 the guys do some catching up and play Where in the Whorld.  They also discuss an email from Simon Cole and inquire on the impact of the recent AI paper on fingerprints.  Then they discuss the TFSC report that followed an investigation into a complaint filed against the latent print contractor(s) in the Joseph Webster case.  The webster case was a homicide cold case that eventually broke with a CODIS hit and a subsequent apparent bloody palm print at the scene of the crime.  Initially the palm print was not identified to Webster, but then after the CODIS hit occurred to Webster and a second person, the latent print evidence was re-visited in 2013, and an identification was declared (pursuant to reviewing additional palm print exemplars of Webster).  Testimony occurred in 2016 by a project manager, but not any of the original examiners.  In 2020, a contractor for the defense was hired to review the case and several examiners were unable to verify the identification.  This conflict, as well as a review of the testimony, sparked a complaint to the TFSC in the case.  The guys review the facts and details of the case in Part 1.
Link to TFSC Report

https://www.txcourts.gov/media/1457617/fir-complaint-2216-rsa-latent-prints-as-of-12623.pdf

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

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 latent prints, forensic art, face comparison, crime scene, and many positions with the IAI. He shares the future of the face discipline and how the IAI is working towards a certification process.

Episode 268 - Steve Johnson Interview

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 childhood, the guys welcome Chloe George from New South Wales Police Force, Australia.  Glenn saw Chloe present at IAFS, where her presentation on phalange pattern classification won best Oral (Presentation).  Chloe introduces a system of phalange pattern classification first described by Marie Ploetz-Radmann in 1937.  She walks us through the system and the 12 general pattern types in phalanges and then also shares her personal data and testing that she performed.

A copy of her IAFS presentation can be found here:
https://docs.google.com/presentation/d/1yrUsOFM5alJV1rQcrTGXiQkDb-3DuWUO/edit#slide=id.p5

Episode 267- Chloe George Interview - Research on Phalange Patterns

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.  They then introduce their guest from the New South Wales Police Force, Andrew Chapman.  Glenn had the benefit of seeing Andy’s presentation at IAFS in Sydney.  Andy presented on a fingerprint black box error rate study conducted with laypeople, trainees, and experts in New South Wales, Australia.  The guys discuss various statistics in the study, especially when comparing across the participant groups.  The Aussie data are very similar to U.S. examiner data and the guys draw some parallels to other research.  The guys also discuss some novel aspects to the study design that make this one such a fascinating study.

Episode 266 - Andy Chapman Interview - Aussie Black Box Study

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. Bethany Growns, a lecturer and psychologist at the University of Canterbury, in New Zealand.  Bethany joins the show to discuss her research on matchers, super-matchers, and research she has conducted with novices (lay people), fingerprint, firearms, and facial recognition experts.  She discusses the advantages of natural ability v. trained expertise and how it impacts one’s ability to perform matching tasks in the expert’s domain v. other domains.  The guys ask questions about how to utilize this research to impact training programs.  Finally, they discuss more aspects of the IAFS conference where Glenn met Bethany.

Growns B, Dunn JD, Mattijssen EJAT, Quigley-McBride A, Towler A. Match me if you can: Evidence for a domain-general visual comparison ability. Psychon Bull Rev. 2022 Jun;29(3):866-881. doi: 10.3758/s13423-021-02044-2. Epub 2022 Jan 7. PMID: 34997551; PMCID: PMC9166871.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9166871/

Other publications by Growns https://www.bethanygrowns.com/publications

Are you a super-matcher?  Test your skills!
Sign up to participate in studies by Dr. Growns:
https://canterbury.qualtrics.com/jfe/form/SV_038MorkGlc9SDoW

Episode 215 - Aging Latent Prints

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