RELATIONSHIP OF PSYCHOLOGICAL, DEMOGRAPHIC, AND LEGAL VARIABLES TO COURT-DECISIONS OF COMPETENCE TO STAND TRIAL AMONG MENTALLY-RETARDED CRIMINAL DEFENDANTS

Competency to stand trial is a constitutional requirement of the due p rocess clause of the Fourteenth Amendment. In the criminal justice sys tem, psychologists play a crucial role in the determination of a defen dant's competency whenever the issue is raised during a criminal trial . This study of 288 criminal defendants diagnosed as mentally retarded explores the construct validity of competency to stand trial by exami ning the potential contributing factors in psychologists 'diagnoses of mental retardation and its relationship to the judges' decisions on c ompetency to stand trial. The results showed that the most important p redictor of judges' decisions on competency to stand trial was psychol ogists' evaluations. Defendants' criminal history and prior experience of incompetency adjudication were also correlated with judges' adjudi cations on competency of current changes. A defendant was less likely to be adjudicated as competent to stand trial if he or she previously had been found incompetent to stand trial. Demographic variables such as race had no relationship to judges' decisions. (C) 1998 Elsevier Sc ience Ltd.