The role and reliability of the Psychopathy Checklist-Revised in U.S. sexually violent predator evaluations: a case law survey.

The civil commitment of offenders as sexually violent predators (SVPs) is a highly contentious area of U.S. mental health law. The Psychopathy Checklist-Revised (PCL-R) is frequently used in mental health evaluations in these cases to aid legal decision making. Although generally perceived to be a useful assessment tool in applied settings, recent research has raised questions about the reliability of PCL-R scores in SVP cases. In this report, we review the use of the PCL-R in SVP trials identified as part of a larger project investigating its role in U.S. case law. After presenting data on how the PCL-R is used in SVP cases, we examine the reliability of scores reported in these cases. We located 214 cases involving the PCL-R, 88 of which included an actual score and 29 of which included multiple scores. In the 29 cases with multiple scores, the intraclass correlation coefficient for a single evaluator for the PCL-R scores was only .58, and only 41.4% of the difference scores were within 1 standard error of measurement unit. The average score reported by prosecution experts was significantly higher than the average score reported by defense-retained experts, and prosecution experts reported PCL-R scores of 30 or above in nearly 50% of the cases, compared with less than 10% of the cases for defense witnesses (κ = .29). In conjunction with other recently published findings demonstrating the unreliability of PCL-R scores in applied settings, our results raise questions as to whether this instrument should be admitted into SVP proceedings.