A practical approach to mitigating cognitive bias effects in forensic casework

Historically, forensic science results have been admitted in court, with minimal scrutiny regarding their scientific validity. However, following the National Academy of Sciences (NAS, 2009) report, the forensic community has undergone a significant transformation. This shift has demonstrated that forensic scientists and laboratories want to ensure the scientific rigor and quality of their results, but that they are often uncertain where to begin when addressing concerns about error and bias. In response to these challenges, the Department of Forensic Sciences in Costa Rica designed and began a pilot program within the Questioned Documents Section of the laboratory. This program incorporates various existing research-based tools, including Linear Sequential Unmasking-Expanded, Blind Verifications, case managers, and other important mitigation strategies to enhance the reliability of and reduce subjectivity in forensic evaluations. This article discusses the journey from initial planning through to implementation and the impact of the strategies that were adopted. The article describes how the Department systematically addressed key barriers to implementation and maintenance after implementation, providing a model to other laboratories for prioritizing resource allocation. This successful pilot program demonstrates that there are feasible and effective changes that can mitigate bias, and this article presents evidence that existing recommendations in the literature can be used within laboratory systems to reduce error and bias in practice.