There are two primary spheres of foundational knowledge that support the latent print discipline: 1) science demonstrating the discriminating power of friction ridge impressions and 2) science demonstrating that trained analysts are capable of providing valid conclusions. While many analysts receive the knowledge portion during training, they often struggle articulating the concepts for the trier of fact.
During this intense five-day course Alice will review key pieces from both spheres that can be used to support testimony and mentor participants on the presentation of these concepts in the courtroom. A few comparison exercises are provided during the week to reinforce the academics and a court case study, woven throughout the week, will illustrate the real-world application of the methods presented. The content of this course is organized into four blocks that logically build on one another:
Empirical Observations and Tacit Knowledge
There is a long history of tacit knowledge and empirical observations supporting the use of friction ridge impressions to identify individuals. Layered behind this tacit knowledge and empirical observation is the biological causation: developmental (genetic) noise. Attendees will learn how developmental noise during fetal development of friction ridges imparts the discriminating power to the ridge arrangements. Attendees will also learn how biological processes can distort the arrangements of the friction ridges and how to recognize (and defend their interpretations of) these distortions. Attendees will prepare and verbally answer questions to lay foundation for the acceptance of fingerprint evidence based on empirical observations and biological concepts.
Measuring the Discriminating Power of Fingerprints
Over the last century, scientists have attempted to measure the uniqueness of fingerprints. Attendees will learn about model making in science and the recommended elements of a robust fingerprint model. Once this foundation is established, attendees will learn about twin studies, historical fingerprint models, pattern and minutia distribution studies, and modern statistical studies. The basic premise and limitations of selected models will be discussed. Attendees will prepare and verbally answer questions to lay foundation for the acceptance of fingerprint evidence without statistics.
The human visual system is complex, but it does follow basic rules and it does learn when a person is repeatedly exposed to visual stimuli (i.e. fingerprints). Attendees will be introduced to the human visual system, theories of experts and expert performance, studies regarding visual expertise in fingerprint analysts, and the explicit and implicit learning that takes place during a training program. Attendees will prepare and verbally answer questions to lay foundation for why an untrained person (e.g. a jury) lacks the requisite expertise to interpret or make inferences from friction ridge comparisons.
A group of recent studies have demonstrated the reliability (and variability) of fingerprint experts. Attendees will be introduced to human factors, error rates (including PCAST’s use of confidence intervals), black box studies of analyst performance, and white box studies of analyst performance. Attendees will prepare and verbally answer questions to lay foundation for the acceptance of fingerprint evidence based on the accuracy and reliability of the analysts (Daubert error rate criteria) and the aspects of a quality management system that support analysts’ performance in casework.