CSAFE invites researchers, collaborators, and members of the broader forensics and statistics communities to participate in our Spring 2022 Webinar Series on Friday, April 22, 2022, from 11:00am-Noon CST. The presentation will be “Shining a Light on Black Box Studies.” 

Presenters:
Dr. Kori Khan
Assistant Professor – Iowa State University
Dr. Alicia Carriquiry
Director – CSAFE

Presentation Description:
The American criminal justice system heavily relies on conclusions reached by the forensic science community. In the last ten years, there has been an increased interest in assessing the validity of the methods used to reach such conclusions. For pattern comparison disciplines, however, this can be difficult because the methods employed rely on visual examinations and subjective determinations. Recently, “black box studies” have been put forward as the gold standard for estimating the rate of errors a discipline makes to assist judges in assessing the validity and admissibility of the analysis of forensic evidence. These studies have since been conducted for various disciplines and their findings are used by judges across the country to justify the admission of forensic evidence testimony. These black box studies suffer from flawed experimental designs and inappropriate statistical analyses. We show that these limitations likely underestimate error rates and preclude researchers from making conclusions about a discipline’s error rates. With a view to future studies, we propose minimal statistical criteria for black box studies and describe some of the data that need to be available to plan and implement such studies.

The webinars are free and open to the public, but researchers, collaborators and members of the broader forensics and statistics communities are encouraged to attend. Each 60-minute webinar will allow for discussion and questions.

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CSAFE invites researchers, collaborators, and members of the broader forensics and statistics communities to participate in our Spring 2022 Webinar Series on Thursday, March 24, 2022, from 11:00am-Noon CST. The presentation will be “Modeling And iNventory of Tread Impression System (MANTIS): The development, deployment and application of an active footwear data collection system.” 

Presenters:
Dr. Richard Stone
Associate Professor – Iowa State University
Dr. Susan VanderPlas
Assistant Professor – University of Nebraska-Lincoln

Presentation Description:
This session will detail the development, capabilities and successful deployment of the Modeling And iNventory of Tread Impression System (MANTIS). MANTIS Optics Scanner takes real time video of gait as the shoe comes in contact with the cover place (again the clear portion). It synchronizes a series of video cameras to create a detailed image of the shoe that can later be processed by software such as Sift + Ransac to create the tread pattern for comparison. The cameras capture between 8 to 15 megapixels for the configuration below (four cameras located in the housing). The use of video optics is expandable to utilize the laser scanning option, though the current utilization focuses on optical capture, thus allowing for tread capture during dynamic movement, i.e. a person walking or running across the system.

The webinars are free and open to the public, but researchers, collaborators and members of the broader forensics and statistics communities are encouraged to attend. Each 60-minute webinar will allow for discussion and questions.

Sign up on the form below (Chrome & Safari web browsers work the best):

CSAFE invites researchers, collaborators, and members of the broader forensics and statistics communities to participate in our Spring 2022 Webinar Series on Thursday, December 9th, 2021, from 9:00-10:00 am CT. The presentation will be “Using Mixture Models to Examine Group Differences: An Illustration Involving the Perceived Strength of Forensic Science Evidence.” 

Presenter:
Naomi Kaplan Damary, PhD
Lecturer – The Hebrew University of Jerusalem

Presentation Description:
Forensic examiners compare items to assess whether they originate from a common source. In reaching conclusions, they consider the probability of the observed similarities and differences under alternative assumptions regarding the source(s) of the items (i.e., same or different source). These conclusions can be reported in various ways including likelihood ratios or random match probabilities. Thompson et. al., 2018 examined how lay people perceive the strength of these reports through the use of paired comparison models, obtaining rank-ordered lists of the various statements and an indication of the perceived differences among them. The current study expands this research by examining whether the population is comprised of sub-populations that interpret these statements differently and whether their differences can be characterized. A mixture model that allows for multiple sub-populations with possibly different rankings of the statements is fit to the data and the possibility that covariates explain sub-population membership is considered. A deeper understanding of the way potential jurors perceive various forms of forensic reporting could improve communication in the courtroom.

Associated Reading:
Insights: Using Mixture Models to Examine Group Differences Among Jurors

The webinars are free and open to the public, but researchers, collaborators and members of the broader forensics and statistics communities are encouraged to attend. Each 60-minute webinar will allow for discussion and questions.

CSAFE invites researchers, collaborators, and members of the broader forensics and statistics communities to participate in our Spring 2022 Webinar Series on Thursday, February 17th, 2022, from Noon-1:00 pm CST. The presentation will be “Improving Forensic Decision Making: a Human-Cognitive Perspective.” 

Presenter:
Itiel Dror
Cognitive Neuroscience Researcher – University College London

Presentation Description:
Humans play a critical role in forensic decision making. Drawing upon classic cognitive and psychological research on factors that influence and underpin expert decision making, this webinar will show the weaknesses and vulnerabilities in forensic decision making. The presenter will also propose a broad and versatile approach to strengthening forensic expert decisions.

Associated Reading:
Linear Sequential Unmasking–Expanded (LSU-E): A general approach for improving decision making as well as minimizing noise and bias

The webinars are free and open to the public, but researchers, collaborators and members of the broader forensics and statistics communities are encouraged to attend. Each 60-minute webinar will allow for discussion and questions.

Sign up on the form below (Chrome & Safari web browsers work the best):

This event took place on September 22, 2021. A recording of the event can be found below.

Presenter:
Simon Cole
Professor – University of California, Irvine

Presentation Description:
Over the past decade, with increasing scientific scrutiny on forensic reporting practices, there have been several efforts to introduce statistical thinking and probabilistic reasoning into forensic practice. These efforts have been met with mixed reactions—a common one being skepticism, or downright hostility, towards this objective. For probabilistic reasoning to be adopted in forensic practice, more than statistical knowledge will be necessary. Social scientific knowledge will be critical to effectively understand the sources of concern and barriers to implementation. This study reports the findings of a survey of forensic fingerprint examiners about reporting practices across the discipline and practitioners’ attitudes and characterizations of probabilistic reporting. Overall, despite its adoption by a small number of practitioners, community-wide adoption of probabilistic reporting in the friction ridge discipline faces challenges. We found that almost no respondents currently report probabilistically. Perhaps more surprisingly, most respondents who claimed to report probabilistically, in fact, do not. Furthermore, we found that two-thirds of respondents perceive probabilistic reporting as ‘inappropriate’—their most common concern being that defense attorneys would take advantage of uncertainty or that probabilistic reports would mislead, or be misunderstood by, other criminal justice system actors. If probabilistic reporting is to be adopted, much work is still needed to better educate practitioners on the importance and utility of probabilistic reasoning in order to facilitate a path towards improved reporting practices.

The data and materials used in this research are publicly available at: https://data.csafe.iastate.edu/ExaminerSurveyStudies/.

Associated Reading:
Insights: Mt. Everest—We Are Going to Lose Many