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Accounting for Individual Differences Among Fingerprint Examiners Using Item Response Theory (304901)

Keywords: fingerprint examination, item response theory, forensic science

Fingerprint examination is an important part of many forensic investigations, and involves examiners comparing a latent print (unknown source) to a reference print (known source) to determine whether the prints were made from the same source. Given the same comparison task, different latent print examiners may come to different conclusions and/or use different criteria for coming to those decisions. There has been an influx of studies attempting to better estimate overall error rates as well as understand decision-making processes in forensic analyses. Item response theory (IRT) can provide valuable insight into these studies by accounting for both individual differences among examiners as well as comparison tasks of varying difficulty. We analyze the FBI ``black box' dataset to better understand how individual differences among examiners, as well as varying difficulty of comparison tasks, may influence latent print analysis decisions. Differences between forensic science and traditional IRT applications are also addressed, including smaller sample sizes, increased privacy protections, sequentially-structured responses, and self-reported assessments of performance.