Use of the Psychopathy Checklist-Revised in Legal Contexts: Validity, Reliability, Admissibility, and Evidentiary Issues

Abstract

The construct of psychopathy has received considerable attention from clinicians, researchers, and legal practitioners because of its demonstrated association with a range of outcomes of interest to the criminal justice system. The Psychopathy Checklist-Revised (PCL-R) is generally regarded as the premier assessment tool for measuring psychopathy in correctional and legal contexts, and the PCL-R is being used with increased frequency to address a variety of legal questions. This article provides a comprehensive examination and review of the PCL-R’s use in legal contexts. We begin by reviewing various uses (appropriate and inappropriate) of the PCL-R in legal contexts, using the risk-need-responsivity (RNR) model as the conceptual framework. After reviewing available data regarding the use of the PCL-R in legal contexts, we review and synthesize psychometric research with psycholegal relevance, with a focus on the PCL-R’s construct validity, predictive validity, and interrater reliability. We then discuss the scientific acceptability and clinical utility of the PCL-R’s structural, predictive, and measurement properties for credibility in court, followed by sample cross-examination questions. We conclude with a review of admissibility issues relating to the use of the PCL-R in various legal proceedings.

Notes

1 As Sullivan et al. (2006) reported average measure ICC values (.94 and .91, respectively) the Spearman Brown prophecy formula was used to convert these to single measure estimates, as reported here. Olver et al. (2018) reported ICC_C1, but ICC_A1 values are reported here (ICC_C1 and ICC_A1 values were generally identical).

2 The k per effect varied depending on consideration for possible study overlap and the correlation metric used, 11 of which reported ICC_A1, 1 reported the equivalent of ICC_C1, and 1 reported both.

3 Daubert is the admissibility standard in all federal courts, and most states have adopted Daubert or a close derivative (see Slobogin et al., 2020).

4 Because a 702 analysis is dependent on the specific expert and the specific nature of the proffered expert evidence in the context of a specific case, we will limit our discussion to whether the PCL-R satisfies the 401/403 admissibility standard in several legal contexts. With that said, we offer the following brief comment regarding the PCL-R and Daubert. If a court determines that PCL-R evidence is relevant (FRE 401) and not unduly prejudicial (FRE 403) in a specific case, we believe the PCL-R could satisfy the four Daubert criteria: testing (PCL-R has been subjected to rigorous empirical analysis in several legal contexts), peer review and publication (well-developed empirical literature regarding the use of the PCL-R in multiple contexts), error rate (discussion of SEM established via meta-analyses and meta-meta-analyses), and general acceptance (use of the PCL-R is generally accepted among practitioners in several contexts). Again, though, we emphasize that the admissibility of expert evidence cannot be discussed in a vacuum because it is dependent on the specifics of each case.