The Law Meets Psychological Expertise: Eight Best Practices to Improve Forensic Psychological Assessment

We review the state of forensic mental health assessment. The field is in much better shape than in the past; however, significant problems of quality remain, with much room for improvement. We provide an overview of forensic psychology’s history and discuss its possible future, with multiple audiences in mind. We distill decades of scholarship from and about fundamental basic science and forensic science, clinical and forensic psychology, and the law of expert evidence into eight best practices for the validity of a forensic psychological assessment. We argue these best practices should apply when a psychological assessment relies on the norms, values, and esteem of science to inform legal processes. The eight key considerations include (a) foundational validity of the assessment; (b) validity of the assessment as applied; (c) management and mitigation of bias; (d) attention to quality assurance; (e) appropriate communication of data, results, and opinions; ( f ) explicit consideration of limitations and assumptions; (g) weighing of alternative views or disagreements; and (h) adherence with ethical obligations, professional guidelines, codes of conduct, and rules of evidence.