Episode 181 – Fingerprint Analogies

    Fingerprint AnalogiesFingerprint Analogies

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.

Double Loop Podcast with Glenn Langenburg and Eric Ray
Podcast for Latent Print Examiners
Your source for everything about fingerprints
While you’re working on your comparisons, we’ll talk about comparisons

Episode 170 – Della Wilkinson Interview

Della Wilkinson Interview

Della Wilkinson Interview

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 episode 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.

Double Loop Podcast with Glenn Langenburg and Eric Ray
Podcast for Latent Print Examiners
Your source for everything about fingerprints
While you’re working on your comparisons, we’ll talk about comparisons

Episode 165 – Categorical vs. Probabilistic

Categorical vs. Probabilistic

Categorical vs. Probabilistic

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?

Double Loop Podcast with Glenn Langenburg and Eric Ray
Podcast for Latent Print Examiners
Your source for everything about fingerprints
While you’re working on your comparisons, we’ll talk about comparisons

Episode 150 – Workplace Stress Article

Workplace Stress Article

Workplace Stress Article

Glenn Langenburg and Eric Ray read through a new paper (Human Factors Effecting Forensic Decision Making: Workplace Stress and Well-being) from Amy Jeanguenat and Itiel Dror on how workplace stress can affect forensic decision making. The paper makes several great points about how forensic scientists deal with many stresses unique to their careers, including facing outside criticism and working in a culture with zero tolerance for errors.

“So then the paper goes on about the unique, industry-specific pressures that are placed on forensic scientists and managers. I really did find these to be actually very accurate and pretty insightful. I’m going to go down the list and I’ll define them and we can talk about them.

The first is technique criticism. Essentially, there are these groups that are coming out like NAS and PCAST that are critically examining the entire field they look at what we do. They all have armchair quarterback status and all have a view on what we do and of course it tends to be highly critical. So they call it technique criticism. But I think of it as external criticism. The second one is just exposure to case details. We work these very violent and sometimes disturbing cases. I don’t know if you’ve ever had to process evidence where you become knowledgeable of details that you wish you had not become intimately familiar with. They can have an effect. I worked crime scenes for a number of years and those things stick with you. Exposures of violent and horrible, terrible things can have a long-lasting effect and cause stress.”

Double Loop Podcast with Glenn Langenburg and Eric Ray
Podcast for Latent Print Examiners
Your source for everything about fingerprints
While you’re working on your comparisons, we’ll talk about comparisons

Episode 149 – White Box Exclusion Article

White Box Exclusion Article

White Box Exclusion Article

Eric Ray and Glenn Langenburg delve deep into the data from the White Box and Black Box studies regarding the exclusion decision (Factors associated with latent fingerprint exclusion determinations). Ulery, Hicklin, Roberts, and Buscaglia publish this data revealing a strong correlation between exclusion accuracy and the presence of a core or delta in both impressions. Glenn and Eric also look at how minutiae count and latent quality affect exclusion accuracy and then discuss the utility of the decision itself. Interesting stuff.

“These are all great numbers. How do you translate this into a system that the examiner can use during comparison that will help decrease errors, improve consistency between different examiner’s about the conclusion that they reach, and provide a basis for comparison that’s easily convertible into some sort of policy you can write down? You can have a somewhat straightforward rule that that can be implemented and improve all these things.

This is why I strongly believe that if with exclusion that it’s hard to look at these different things. So you find the thing in both prints that’s the same (the delta or the core). If both prints have one, then that’s the same in both. Then look for clear minutiae around it that are different then you have yourself an exclusion. I think that mindset can be written down to improve consistency between examiners and it hits all these things. It hits the core, the delta, the number of minutiae, and the LQ Metric.”

Double Loop Podcast with Glenn Langenburg and Eric Ray
Podcast for Latent Print Examiners
Your source for everything about fingerprints
While you’re working on your comparisons, we’ll talk about comparisons