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PAPERS

Langenburg, G; Bochet, F; Ford, S.  A Report of Statistics from Latent Print Casework.  Forensic Science Policy & Management: An International Journal (2014) 5 (1-2), 15-37.  http://dx.doi.org/10.1080/19409044.2014.929759
Abstract:

Statistics were derived from casework from the Minnesota Bureau of Criminal Apprehension Latent Print Unit. These data represented a portion of the latent print casework completed in the 2003/2004 calendar years (N = 673 cases) and 2009/2010 calendar years (N = 885 cases). The 2003/2004 data revealed latent print recovery rates from various exhibits. Identifiable latent prints were recovered 13% of the time on firearms, 13% of the time on plastic bags, and no identifiable latent prints were recovered from fired or unfired ammunition. The processing of evidence prior to submission to the laboratory increased the chances of latent print recovery. Both data sets were explored for the rate at which identifiable latent prints were reported (61% of cases in 2003/2004 and 54% of cases in 2009/2010) and the rate at which identifiable latent prints were subsequently identified to an individual in the case (23% of cases in 2003/2004 and 25% of cases in 2009/2010). There was no noticeable difference for the identification rate in property crimes versus crimes against people.

The 2009/2010 data were explored for possible effects from analysts having access to contextual information or significant interaction and communication with police officers or prosecutors while working a case. We noted that 2% of cases in the data qualified for this condition—the majority of BCA-LPU cases are worked without contextual information or police interaction. Comparing high context/high interaction cases versus no context/no interaction cases, we found the latent print identification rates to be equal (21% versus 22%, respectively).

Langenburg, G.  The consideration of fingerprint probabilities in the courtroom.  Australian Journal of Forensic Sciences (2013) doi: 10.1080/00450618.2013.784360
Abstract:

Recent criticisms and challenges to fingerprint evidence in the United States have prompted fingerprint examiners to reconsider the notion of using probabilities in the courtroom. A growing number of examiners are interested in learning more about this approach, but there is still considerable inertia and fear with respect to this paradigm shift. The present paper provides the author’s viewpoints on why the community can and should be moving in this direction. These viewpoints were shaped through personal experiences as a case-working fingerprint examiner, an instructor of other examiners, and the author’s participation in a moot court exercise that delivered fingerprint probabilities to non-forensic laypersons acting as mock jurors.

Praska, N; Langenburg, G.  Reactions of latent prints exposed to blood.  Forensic Science International (2012) 224, 51-58.  http://dx.doi.org/10.1016/j.forsciint.2012.10.027
Abstract:

We explored whether an undeveloped latent print (fingermark) exposed to blood and later developed by enhancement with blood reagents such as amido black (AB) or leucocrystal violet (LCV) could appear as a genuine blood mark. We examined three different experimental conditions. In Experiment I, fingermark residue only was tested, as a control to confirm that fingermark residue alone does not react with the blood reagents AB and LCV. Experiment II investigated whether latent fingermarks exposed to blood dilutions could be treated with AB or LCV and subsequently appear as a genuine blood mark enhanced with AB or LCV. Experiment III tested whether latent fingermarks exposed to whole blood could be processed with AB or LCV and subsequently appear as a genuine blood mark enhanced with AB or LCV.

The present study found that indeed, fingermark residue alone does not react with the blood reagents AB and LCV. In Experiment II, an interaction occurred between the fingermark residue and the diluted blood that caused the ridges to appear a red color. In the present study, this interaction is called a faux blood mark. While the faux blood mark phenomenon occurred most often following exposure to diluted blood, it did not occur consistently, and a predictable pattern could not be established. However, the reaction occurred more frequently following extended fingermark residue drying times. Faux blood marks are distinguishable from genuine blood marks prior to enhancement with blood reagents. Following treatment with blood reagents, it became increasingly difficult to determine whether the enhanced mark was a genuine blood print or a latent fingermark exposed to diluted blood. Latent fingermarks exposed to whole blood often resulted in a void prior to enhancement, but following treatment with blood reagents, were difficult to distinguish from a genuine blood mark enhanced with blood reagents.

Langenburg, G.  A Critical Analysis and Review of the ACE-V Process. Ecole des Sciences Criminelles (ESC)-Institut de Police Scientifique (IPS), University of Lausanne, Switzerland, PhD thesis (2012).
Download at: http://www.unil.ch/esc/page18345.html

Ray, E. Frequency of Patterns in Palms. Journal of Forensic Identifcation (2012), 62 (6), 568-587.
Abstract:

The left and right palms of 499 individuals were clas- sified for Level 1 pattern frequency in the interdigital, thenar, and hypothenar areas to establish a basic system for classifying palmprint patterns. Significant differences were observed in the frequency of patterns between right and left palms in the interdigital and thenar areas (p < 0.001), but there were no significant differences in the fre- quency of patterns between right and left hypothenar areas (p > 0.05). Symmetry between the right and left palms of an individual was noted in each area of the palm. The established palm classification system could be adapted to improve searches in the next generation of auto- mated palmprint identification systems (APIS). To fully realize the capabilities of an APIS, many agencies will need additional training in how to record more complete palmprints.

 

PRESENTATIONS

Bias Effects in Forensic Science
Glenn Langenburg
February 2015 – AAFS 67th Annual Scientific Meeting
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Case Specific AFIS – A tool for reducing errors
Glenn Langenburg & Carey Hall
August 2014 – IAI Educational Conference
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Reducing Erroneous Exclusions: The Workshop
Eric Ray & Penny Dechant
August 2013 – IAI Educational Conference
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You Mean There’s Another Way? – Alternate Latent Workflows
Penny Dechant & Eric Ray
August 2013 – IAI Educational Conference
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Exclusions and Sufficiency: Challenging Decisions, A Multitude of Viewpoints and Uncomfortable Change
John Black & Glenn Langenburg
August 2013 – IAI Educational Conference
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Exclusions: Policy, Ethics, and Law
Carey Hall
August 2013 – IAI Educational Conference
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Reactions of Latent Prints to Blood
Nicole Praska
August 2013 – IAI Educational Conference
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Recent Research Demonstrating the Accuracy, Reliability, and Validity of Friction Ridge Examinations
Glenn Langenburg
September 2013 – Colloque international sur la criminalistique, Quebec, Canada
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Presenting Probabilities in the Courtroom: A Moot Court Exercise
Glenn Langenburg
September 2013 – Colloque international sur la criminalistique, Quebec, Canada
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The Integration of Technology and ACE-V
Glenn Langenburg
March 2014 – FPS Annual Conference
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