Psychological perspectives on problems with forensic science evidence.

Abstract

Psychology has, for the most part, been deemed as irrelevant to the work of forensic science, resulting in the neglect of the crucial and central role of the human examiner. Conceptualized as objective and as an exact science, infallible with zero error rates (e.g., Ashbaugh, 1994;Cole, 2005;Evett, 1996; Federal Bureau of Investigation [FBI], 1985), forensic science has failed to properly acknowledge that in many forensic disciplines the human examiner is the instrument of analysis (see Figure 12.1). In such disciplines (e.g., fingerprints, shoe and tire marks, blood stains, ear prints, handwriting, firearms, hair, bite marks), it is up to the human examiner to make judgments and interpretations of visual patterns. The determinations in such disciplines often lack measurements (Dror, 2009a) and are based on a subjective assessment by the human examiner (e.g., "sufficient similarity" between two patterns, usually one collected from the crime scene and the other from a suspect). They pertain even to examinations where part of the analysis is done by instruments, as is

Unpacking Workplace Stress and Forensic Expert Decision-Making: From Theory to Practice

“…After we absorb information via bottom-up processing, that information travels from the sensory organs (e.g., eyes) to the brain and cognitive system where we interpret it via a complementary process called top-down processing (Dror & Bucht, 2012;Kassin et al, 2013). During this process, different people (or even the same person at different times) may evaluate and interpret the same information in different ways (e.g., notice different features and/or reach different conclusions about the same evidence; Dror, 2023) depending on their knowledge, experience, expectations, motivations (Kassin et al, 2013)-and indeed, stress level (Jeanguenat & Dror, 2018).…”

Quality of Laypersons' Assessment of Forensically Relevant Stimuli,

“…This process allows for ambiguous details to be erroneously identified as points of similarity between the two prints. Although forensic science plays a critical role in criminal investigations like the Mayfield case, recent analyses of DNA exonerations reveal that errors in forensic comparisons are a contributing factor to wrongful convictions (2). Pattern disciplines such as fingerprints, shoeprints, and toolmarks may be more susceptible to the effects of bias, especially when stimuli are ambiguous (3).…”