Assessment of Competence to Stand Trial

Competence to stand trial has long been considered “the most significant mental health inquiry pursued in the system of criminal law” (Stone, 1975, p. 200). Hoge, Bonnie, Poythress, and Monahan (1992) estimated that pretrial competence evaluations are sought in 2% to 8% of all felony cases. LaFortune and Nicholson (1995) reported that judges and attorneys estimate that competency is a legitimate issue in approximately 5% of criminal cases, although only two thirds of these defendants whose competency is questionable are actually referred for competency evaluations. The frequency of trial competency evaluations in the United States has steadily increased, from the 1978 estimate of 25,000 annually (Steadman, Monahan, Hartstone, Davis, and Robbins, 1982) to more recent estimates of 50,000 to 60,000 defendants evaluated for trial competency (Bonnie & Grisso, 2000; Skeem & Golding, 1998). Approximately 20% to 30% of defendants referred for competency evaluation are adjudicated incompetent to stand trial. Representative studies include the 30% rate of findings of incompetence over a 25-year period reported for the meta-analysis by Nicholson and Kugler (1991); the 18% rate for federal defendants (Cochrane, Grisso, & Frederick, 2001); rates of 13%, 18%, and 29% for defendants evaluated in Virginia, Michigan, and Ohio, respectively (Warren, Rosenfeld, Fitch, & Hawk, 1997); and the overall rate of 19% for statewide samples in Virginia and Alabama (Murrie, Boccaccini, Zapf, Warren, & Henderson, 2008). These findings also indicate that rates of incompetence recommendations vary as a function of examiner, evaluation setting (i.e., inpatient versus outpatient), and the level of impairment of defendants referred. Cooper and Grisso (1997) noted that referrals for inpatient competence evaluations—as well as incompetence adjudications—may have become a mechanism for hospitalizing persons with mental illness who could not otherwise access inpatient care. This observation is supported by research indicating that defendants who are charged with misdemeanors and are referred for evaluation are more likely to be adjudicated incompetent to proceed than are defendants charged with felonies (e.g., Warren et al., 2006). Similarly, Stafford and Wygant (2005) reported that 78% of defendants referred for competency evaluation by a misdemeanor mental health court were found incompetent and hospitalized for competency restoration—a rate considerably higher than general rates of incompetence adjudication (see immediately above). The growing movement toward specialty courts, including mental health courts (Redlich, Steadman, Griffin, Petrila, & Monahan, 2005), may contribute to an increased number of competence evaluation referrals of defendants who have been identified as having mental disorders, but who lack the capacity to agree to, or to comply with, alternative court proceedings and directives. This chapter begins with a discussion of the legal framework of competence to stand trial, followed by consideration of the conceptual formulations of the legal standards that guide psychological assessments of trial competence. After the empirical literature on variables relevant to trial competence is reviewed, evaluation issues,