Joe Zemmels, an Iowa State University statistics graduate student, was one of two outstanding poster winners in the Young Forensic Scientists Forum at the American Academy of Forensic Sciences (AAFS) annual scientific conference. The conference was held Feb. 13-18 in Orlando, Fla.
Zemmels is a student researcher at the Center for Statistics and Applications in Forensic Evidence (CSAFE) and studies under CSAFE researcher Heike Hofmann, a professor of statistics and professor-in-charge of data science at Iowa State University and co-author of the poster. Susan VanderPlas, a CSAFE researcher and assistant professor of statistics at the University of Nebraska-Lincoln, was also a co-author.
His poster, “Visual Diagnostics for Cartridge Case Impression Evidence,” details the diagnostic tools he, Hofmann and VanderPlas created that help explain the behavior of automatic cartridge case comparison algorithms.
“This research was primarily born out of our own confusion about what a comparison algorithm ‘looks at’ when it returns a similarity score for two cartridge cases,” Zemmels explained. “Before these algorithms are applied in casework, we believe it important that forensic examiners and researchers are able to justify to themselves how an algorithm arrived at a similarity score.”
Zemmels said they also developed an interactive web application called “cartridgeInvestigatR” to give non-programmers access to the algorithms and diagnostic tools.
“Our results indicate that the visual diagnostics can be used to intuitively assess the similarity between two cartridge cases and predict the similarity score output by a comparison algorithm,” he said.
According to Zemmels, this project will be useful for firearm and toolmark examiners and researchers because it will provide alternative methods for visualizing and comparing cartridge case impression evidence than a standard comparison microscope.
Zemmels said they would continue to improve the cartridgeInvestigatR web application to give non-programmers access to these tools. In addition, they are currently developing a free, open-source R package called “impressions” that will allow programmers to use these visual diagnostic tools in their cases.
Attending the AAFS conference was a valuable experience for Zemmels. “It was nice to learn that there are people outside of CSAFE that are just as passionate about creating accessible comparison algorithms.”
An interactive version of Zemmels’ poster is available on CSAFE Learning. Viewers can click on different poster sections to hear Zemmels explain his research in more detail.
He will also discuss this research in an upcoming CSAFE webinar on March 29 at 11 a.m.-noon CT. The webinar is free and will allow for discussion and questions. To enroll, visit https://learn.forensicstats.org.
CSAFE was an exhibitor at the AAFS conference, and many CSAFE researchers presented research during workshops and scientific and poster sessions. More information about CSAFE attending the AAFS conference can be found at https://forensicstats.org/news-posts/csafe-will-exhibit-and-present-research-at-the-2023-aafs-annual-conference/.
Learn more about CSAFE’s work on firearms and toolmarks analysis and find discipline-specific publications and webinars at https://forensicstats.org/firearms-and-toolmark-analysis/.