Psychology, Public Policy, and Law Copyright 1999 by the American Psychological Association, Inc. 1999, Vol. 5, No. 1,120-174 1076-8971/99/S5.00 DOI: 10.1037//1076-8971.5.1.120 EXPERT TESTIMONY AND PROFESSIONAL JUDGMENT Psychological Expertise and Commitment as a Sexual Predator After Hendricks Robert F. Schopp, Mario J. Scalora, and Marc Pearce University of Nebraska—Lincoln Clinicians and social scientists exercise judgments and discharge responsibilities while fulfilling several different roles in interaction with a variety of legal institutions. The decisions of the Supreme Court in Daubert and Hendricks provide an opportunity to examine the defensible parameters of several of these roles. Daubert provides criteria for the admission of expert testimony in a variety of hearings, including commitment hearings held under statutes such as that at issue in Hendricks. The authors interpret these Daubert criteria as representing broader underlying principles that can provide useful guidance in establishing defensible parameters of participation in a variety of legal institutions by clinicians and social scientists. I. Introduction The intersection of two decisions by the U.S. Supreme Court provides an interesting opportunity to reflect on the principles governing the appropriate role of psychological expertise in the adjudication of civil commitment under sexual predator statutes specifically, and in the operation of legal institutions more generally. In Daubert v. Merrell Dow Pharmaceuticals, Inc., the Court articulated a standard for the admission of scientific evidence that calls on the trial judge to ensure that such testimony "rests on a reliable foundation and is relevant to the task at hand." 1 More recently in Kansas v. Hendricks, the Court upheld a statute that authorizes civil commitment of certain sexual offenders who have been convicted of sexual offenses and served their criminal sentences. 2 Commitment under the statute at issue in Hendricks requires that the state establish that the subject of the commitment hearing suffers from a mental abnormality or personality disorder and that this disorder renders the person likely to commit sexual offenses. 3 Psychologists and other mental health professionals routinely testify as expert witnesses in hearings held to determine whether the subjects of the commitment petitions meet these criteria. Robert F. Schopp, College of Law and Department of Psychology, University of Nebraska; Mario J. Scalora, Department of Psychology, University of Nebraska; Marc Pearce, College of Law University of Nebraska. We are grateful to Mike Quattrocchi, Bruce Sales, Dan Shuman, and Barb Sturgis for helpful comments on prior drafts of this article. Correspondence concerning this article should be addressed to Robert F. Schopp, College of Law, University of Nebraska, P.O. Box 830902, Lincoln, Nebraska 68583. ! 509 U.S. 579, 597 (1993). 2 Kansas v. Hendricks, 117 S. Ct. 2072 (1997). 3 Id. at 2077. 120 This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.