Double Loop Podcast

Glenn Langenburg and Eric Ray delve into the second season of Making a Murderer. They start by reviewing the evidence that they had discussed from the first season and then discuss their impressions of the new characters in the docu-series. They then move into a detailed discussion of the experiments conducted by Kathleen Zellner and her new forensic experts on behalf of Steven Avery. The blood and bloodstain patterns are covered. (This episode is sponsored by IDEMIA.)

Glenn Langenburg and Eric Ray are joined by John Swartz, retired from the Tucson Police Department, for a discussion on the Prime Time Rapist case from the mid-1980's. John talks about how the series of 30 attacks on 90 people affected the Tucson community and the department investigating the crimes. Before the perpetrator could be caught, there was a fingerprint examination error that led to other mistakes and civil rights violations. After discussing the details of the case, Glenn and Eric ask John about how the error affected the examiner, the latent print unit, and how the unit was treated by other agencies after the error.

Eric Ray and Glenn Langenburg begin the episode with a discussion of an article from a law journal by Barbara Spellman titled, Communicating Forensic Evidence: Lessons from Psychological Science. Among her main points are that statistics, likelihood rations, and random match probabilities are terrible ways of communicating information to juries. She goes on to say that there are a number of misconceptions in latent fingerprint comparisons that must be addressed to juries and that analogies might be a better way to convey information to them. While Glenn and Eric agree and disagree with some of those points, they conclude the episode by reviewing a number of their favorite analogies that they use when testifying or teaching. (This episode is sponsored by IDEMIA.)

Glenn Langenburg and Eric Ray report on a heated and controversial topic that caught the attention of the latent print world in the summer of 2018, the re-designed IAI Re-Certification test. Every five years, Certified Latent Print Examiners must take a comparison test. The old one was notoriously easy, but that has recently changed, and the error rate was higher than some expected. Carl Speckels raised the topic on the CLPEX.com message board and it was discussed at length at the 2018 IAI Conference. The topic is discussed even further here with some suggestions on how to improve the test while keeping it an important aspect of latent print examination. (This episode is sponsored by IDEMIA.)

Glenn Langenburg and Eric Ray interview Teresa Wu from IDEMIA about the new product launch of IDEMIA's Case AFIS. The new system can quickly scan in exemplar prints from any type of standard or non-standard cards which then serve as a mini-database for an AFIS search. Efficiency is vastly improved when the computer takes care of the searching aspect of latent print comparisons. This process can also almost eliminate erroneous exclusions from casework. (This episode is sponsored by IDEMIA.)

Glenn Langenburg and Eric Ray try to wrap up any final discussion points from The Staircase docu-series. After Michael Peterson's conviction was overturned and a new trial was ordered, new attorneys come in, but an Alford plea is reached and Michael Peterson is released. Should a retrial have gone forward? What decisions did the original judge regret? What mistakes did the prosecution make? What is a blowpoke? And could an owl have been the murderer and/or the murder weapon? (This episode is sponsored by IDEMIA.)

Glenn Langenburg and Eric Ray are graciously joined by Bart Epstein in an interview about bloodstain and other forensic evidence from the trial of Michael Peterson in the death of Kathleen Peterson. Bart Epstein explains his involvement in the case, his opinions on the blood evidence, and where he agreed and disagreed with Duane Deaver and Dr. Henry Lee. This episode is also sponsored by IDEMIA and their new product, Case AFIS.

In our second dive down The Staircase, Eric Ray and Glenn Langenburg start looking closely at all of the forensic evidence available in the case and what it all means. The documentary leaves lots of questions that we try to answer in this episode like: Can you trace an impact back to a point in space? Could the wall, rail, or step have caused all of the impact sites? Where was the defense medical examiner expert? Did the prosecutor have other bloodstain experts ready to testify besides Deaver? Was there castoff? Were there other wounds besides the scalp lacerations? Was it valid to say that there were no other beating deaths without brain or skull injuries? Was there a cleanup? Were the shorts cleaned? Were Deaver's experiments valid? What about his shirt? Quote from the episode, "People need to hear this evidence. Because I think when you watch these documentaries, you're back and forth. And if you're really suspicious of law enforcement, then you come out of this going, 'This guy got railroaded.' This guy w

Eric Ray and Glenn Langenburg focus their forensic science backgrounds on the infamous Kathleen Peterson murder as it was portrayed in The Staircase. The guys review their initial impressions of the case and the documentary and then tell the basic outlines of the story where Michael Peterson is suspected, arrested, charged, and convicted of the murder of his wife. There are so many twists and turns to this story that we had to get them all out of the way in this episode before focusing on the forensics in upcoming episodes.

Glenn Langenburg and Eric Ray return to the annual IAI conference in San Antonio to talk to attendees about the interesting lectures and workshops that they've seen this year. Morgan Hays from Florida talks about how he stays current with the field as a supervisor and how the exclusion and verification topics were covered at the conference. Do you trust your verifier? Linda Manigault from Nevada then joins the conversation and discusses the workshops on FRStat and statistical models that she attended. Glenn ends the episode with a BIG announcement!

Glenn Langenburg and Eric Ray wrap up the three-part discussion on the AAAS Report on the Quality and Gap Analysis of Latent Fingerprint Examination. Surprisingly, the guys agree with many of the recommendations and conclusions in the document with an occasional quibble or clarification. As was hinted in the past two episodes, there are more serious concerns with the report's suggested language and proposed limitation of the word "identification".

Glenn Langenburg and Eric Ray continue the discussion on the pros and cons of the AAAS report. Carey participated with the review of the report and discusses the positive recommendations and the limitations that come from the report not being published in a traditional peer-reviewed journal. After that discussion wrapped up, Carey, Eric, and Glenn get a little off-topic and talk about attending AFIS Users' Conferences. Carey and Glenn presented at the most recent Idemia conference on the benefits of the Case AFIS system. Eric talks about a local AFIS conference and user discussions on how data analysis can lead to improved search practices.

Glenn Langenburg and Eric Ray finally get around to discussing the report on latent fingerprint comparisons from the American Association for the Advancement of Science. John Black (from Black and White Forensics) was on the committee that wrote the report and joins the discussion on some of the merits and limitations of the paper. While many of the research recommendations are the next steps that the latent print field needs, they are also the same recommendations made by other reports. One of the report's main failures is the suggested wording for the identification decision.

Glenn Langenburg and Eric Ray are joined by Della Wilkinson from Canada to discuss the final resolution of the Bornyk case from British Columbia. Originally, Judge Funt (see Double Loop Podcast episdoe 10) ruled that the fingerprint evidence would not be admitted after conducting his own study of latent prints and his own comparison. The Crown appealed and a new trial began with the original examiner, the verifier, Della, and Simon Cole. This episode the Double Loop Podcast also pays tribute to Tony Cantu. He will be missed.

Eric Ray sits down for an interview with Simon Cole from the University of California Irvine. Simon explains how he first became interested in forensics and in latent print comparisons in general, and then outlines the history of his criticisms of the field. Glenn Langenburg later joins Eric for a review of the interview and some of Glenn's perspectives on how Simon's criticisms and the latent print response have both evolved over time.

Glenn Langenburg and Eric Ray continue their interview with Matt Marvin from Ron Smith and Associates about the erroneous identifications and eventual exoneration of Beniah Alton Dandridge. This video (available on YouTube via RayForensics.com) goes through an in-depth and technical review of the latent prints, the errors, the exclusions to Dandridge, and the eventual identifications to the victim's son (who discovered the body).

Eric Ray hosts a live Double Loop Podcast discussion at the 2017 Florida Division IAI Conference in Panama City Beach, FL, and Glenn Langenburg joins via phone for the discussion. The audience hit Eric and Glenn with a variety of questions and the conversation swings from AFIS automation to using AFIS as a support for an identification decision. From the requirements that Florida courts put on latent print examiners to how to keep improving yourself so that you can make that jump into a career in forensics.

Eric Ray and Glenn Langenburg are joined by Matt Marvin of Ron Smith and Associates to discuss in greater detail the details of the Beniah Dandridge case. Matt discusses how he and RSA got involved in the case, the history of the Manning murder, the original investigation, the Dandridge trial, his appeals, RSA's involvement, and Dandridge's eventual release. Check back to RayForensics.com soon for a YouTube video detailing the comparisons in this case.

Eric Ray and Glenn Langenburg discuss two forensic cases that have been in the news in the past few years. First, the guys talk about the recent Golden State Killer case. How did DNA testing and genealogy combine to solve these 40 year old crimes? What databases were accessed and was it ethical to do so? Secondly, Eric and Glenn discuss how accessing profiles of Y chromosomes from online sites led Idaho Falls detectives to Michael Usry, Jr. In 1996 Angie Dodge was murdered and Chris Tapp has been in prison for decades, but things get turned upside down when new technology comes into play.

Glenn Langenburg and Eric Ray tackle two articles in one fantastic episode. First, "Lay Understanding of 'Identification': How Jurors Interpret Forensic Identification Testimony" by Henry Swofford and Jessica Cino from the Journal of Forensic Identification. Secondly, the guys tackle a paper from the Journal of Forensic Sciences, "Comparing Categorical and Probabilistic Fingerprint Evidence" by Brandon Garrett, et al. The big question is: should we say "identification" or should we express the same conclusion in a probabilistic manner?