Competency to Stand Trial

The legal standard for competency to stand trial in the United States was articulated by the U.S. Supreme Court in Dusky v. United States (1960), wherein the Court determined that a defendant must have “sufficient present ability to consult with his lawyer with a reasonable degree of rational understanding” and a “rational as well as factual understanding of the proceedings against him” (p. 402). Mental health professionals are called on to assist the courts by evaluating defendants’ competency to stand trial, often aided by assessment tools designed specifically for this purpose, and by providing treatment for the restoration of competency in incompetent defendants. Psychological research in this area has examined the reliability of competency assessments, the characteristics of defendants deemed incompetent to stand trial, and the characteristics associated with restorability.

Competency to stand trial is the most common type of criminal forensic evaluation, with approximately 60,000 evaluations conducted annually in the United States. That is, between 2% and 8% of all felony defendants are referred for evaluations of competency to stand trial each year. The issue at stake in an evaluation of competency to stand trial is the defendant’s current mental functioning; this is often confused with criminal responsibility (insanity), wherein the issue at stake is the defendant’s mental state at the time of the offense. The prohibition against trying an incompetent defendant dates back to at least the 17th century and serves the dual purpose of ensuring a fair trial for the defendant and preserving the dignity of the adversarial process.

Competency to stand trial is but one type of competency that falls under the larger, more encompassing headings of adjudicative competence or competency to proceed. The issue of a defendant’s competence may be raised at any point in the proceedings before a verdict is rendered; thus, competency to confess (waive Miranda rights), competency to plead guilty, competency to waive the right to counsel, and competency to stand trial all fall under the umbrella of adjudicative competence or competency to proceed. Furthermore, the U.S. Supreme Court in Godinez v. Moran (1993) indicated that the standards for the various types of criminal competencies (pleading guilty, waiving counsel, and standing trial) were to be the same. Thus, in light of the decision in Godinez as well as the fact that upward of 90% of criminal cases are resolved through the plea bargaining process rather than by going to trial per se, evaluations of competency to stand trial necessarily include evaluation of the defendant’s ability to plead guilty and to engage in the plea bargaining process. The term competency to stand trial has begun to be replaced by the term competency to proceed in some states, but for the purpose of remaining true to the literature and commentary that have developed up to this point, the term competency to stand trial is used in this research paper.

Legal Standard and Procedures

Since 1960, every state has adopted the Dusky standard either verbatim or with minor variations in the wording. In addition, some states have elaborated their competency statutes to include articulated standards wherein various specific factors that must be addressed by evaluators in a competency evaluation are set out.

The issue of a defendant’s competency to stand trial may be raised by any party to the proceedings (the defense, the prosecution, or the court more generally), although in the vast majority of cases the issue is raised by the defense. A formal inquiry into a defendant’s competency to stand trial must take place if a “bona fide doubt” about his or her competency exists, as all defendants are presumed competent.

Competency evaluations historically occurred in inpatient settings; however, the majority of competency evaluations now occur in community-based settings, including mental health centers, private practice offices, and jails. Research has indicated that approximately 20% (although this varies by jurisdiction) of all defendants referred for competency evaluation are deemed incompetent; thus, the vast majority of referred defendants are competent to stand trial. Various explanations for the high rate of competence have been put forth, including defense attorneys using the referrals as “fishing expeditions” to attempt to gather information that may be helpful in their defense or to investigate the feasibility of a later insanity plea. Others suggest that these referrals are made to prolong the amount of time it takes to get to trial, thus giving the defense (or perhaps the prosecution) more time to prepare the case; to have a mentally ill defendant hospitalized or treated when he or she will not voluntarily undergo hospitalization or treatment; or so that prosecutors and/or defense attorneys may guard against the possibility of a later appeal on the grounds that an individual with a known history of mental illness was allowed to proceed to trial under the presumption of competence. It is unclear how often the aforementioned reasons serve as the primary rationale for requesting a competency evaluation. In addition, it is important to acknowledge that the procedures used in various jurisdictions may account for the differing rates of incompetence. For example, in jurisdictions that use a screening process to eliminate those who are clearly competent from further evaluation, a higher rate of incompetence would be expected among defendants who undergo a formal evaluation of competency to stand trial.

Depending on the jurisdiction, one or more mental health professionals will evaluate a defendant’s competency to stand trial and submit the results of this evaluation to the court in the form of a written report. A hearing on the issue of competency may take place; however, in most instances, this does not occur. Instead, the court usually renders a decision regarding the defendant’s competency on the basis of the mental health professional’s report. Although the determination of a defendant’s competency status is a legal decision, research has shown that the courts typically concur with the opinion of mental health professionals. In fact, some research has indicated rates of agreement between the court and the evaluator to be greater than 95%.

Defendants who are found competent by the court will proceed with their case, whereas those who are found incompetent will, in most instances, be ordered by the court to undergo treatment for the purpose of restoration of competency. Treatment for restoring a defendant’s competency to stand trial most often occurs on an inpatient basis, although some states have moved toward a “least-restrictive” alternative, which allows for the possibility of outpatient treatment. Generally, most defendants are restored to competency within a 1-year period. Once restored, the defendant resumes with his or her legal proceedings. Those defendants who cannot be restored to competency will generally have their charges dismissed or nolle processed.

Until the 1970s, incompetent defendants were often committed to lengthy periods of confinement in state maximum-security units, even though they were neither tried nor convicted of a crime. In 1972, the U.S. Supreme Court in the case of Jackson v. Indiana decided that incompetent individuals could not be held for “more than a reasonable period of time necessary to determine whether there is a substantial probability” that they will regain competency in the foreseeable future (p. 738). The Court, however, did not give any indication as to what might be considered a “reasonable” period of time. As a result of the Jackson decision, many states amended their statutes to include either language similar to Jackson or specific timelines for determining whether someone might be restored to competency.

With respect to the issue of medication, the U.S. Supreme Court in a series of decisions has indicated that a defendant may be forcibly medicated to restore competency under certain conditions, including an “overriding justification and a determination of medical appropriateness” (Riggins v. Nevada, 1992); its being essential to the safety of the defendant or the safety of others (Riggins v. Nevada, 1992; Washington v. Harper, 1990); or a finding that the medication is likely to restore competency and will not result in side effects that might affect a defendant’s ability to assist counsel and alternative and less intrusive methods are not available (Sell v. United States, 2003). Thus, for the purpose of restoring competency, it seems that the right of a defendant to refuse medication is significantly limited. In this instance, it appears that the government’s interest in trying a competent defendant carries more weight than a defendant’s right to refuse medication.

Competency Evaluation

At its most basic, the evaluation of a defendant’s competency to stand trial involves an assessment of the psycholegal abilities required of the defendant (as per the relevant legal statutes of the jurisdiction), an assessment of the current mental status of the defendant, and a determination of whether a linkage exists between any psycholegal deficits that may be evident and any mental disease or defect that may exist. Thus, a mental disease or defect serves as a prerequisite for a determination of incompetency, and any deficits in the relevant psycholegal abilities must be linked to this mental disease or defect. In addition, the evaluation of these components must occur within the specific context of the defendant’s particular case. That is, the complexities of the particular case must be considered as well as, and in conjunction with, the specific abilities of the particular defendant.

Numerous forensic assessment instruments have been developed to aid in the evaluation of competency to stand trial. A full review of these instruments is beyond the scope of this research paper, but the interested reader is referred to the cross-references listed below for more information. The instruments that have been developed range from simple checklists with little to no empirical support to detailed measures that have been developed and investigated with the highest level of scientific rigor. Some tools, such as the Fitness Interview Test-Revised, can be used either as a screen to help systematically identify individuals in need of further evaluation or as a means of structuring a more detailed competency evaluation. Others, such as the MacArthur Competence Assessment Tool-Criminal Adjudication or the Evaluation of Competence to Stand Trial-Revised, provide for a detailed assessment of competency-related abilities, to be used in conjunction with additional assessment with respect to the defendant’s particular case. In addition, other instruments have been developed for use with specific populations of defendants, such as the Competence Assessment for Standing Trial for Defendants with Mental Retardation.

Research has demonstrated that there is generally good agreement among evaluators with respect to overall decisions regarding competency; however, examiner agreement falls significantly when specific psycholegal deficits are examined. Research has indicated that examiner agreement reaches 80% or higher for overall decisions regarding competency but that it falls to about 25% across a series of competency domains. Of course, it is the more difficult cases, the gray-area cases in which competency is truly a serious question, that are of the greatest concern and for which no research is available.

Given the low base rate of incompetence, high levels of agreement among examiners on the issue of a defendant’s overall competence are to be expected; however, high levels of reliability do not ensure that valid decisions are being made. Validity is difficult to assess because of the criterion problem; that is, there is no true criterion for competency and thus no way to determine whether decisions that have been made about a defendant’s competency are accurate. It is impossible to fully assess predictive validity as only those defendants who are considered competent are allowed to proceed; thus, we have no way of knowing whether a defendant who was considered incompetent was actually unable to perform the abilities required of him or her.

Characteristics of Incompetent Defendants

The vast majority of the research that has been conducted on competency to stand trial has examined the characteristics of and differences between competent and incompetent defendants. The constellation of characteristics held in common by defendants referred for evaluations of competency include being male, single, or unemployed; living alone; having a history of contact with both the criminal justice and the mental health systems; and being diagnosed with a major mental disorder.

The individuals who are found incompetent to stand trial generally show the following characteristics: poor performance on psychological tests that measure a defendant’s legally relevant functional capacities, a diagnosis of psychosis, and psychiatric symptoms indicative of severe psychopathology. In addition, diagnoses of schizophrenia, mental retardation, mood disorders, and organic brain disorders have all been found to be strong predictors of incompetency.

Direct comparisons of competent and incompetent defendants reveal that incompetent defendants are significantly more likely to be single, unemployed, charged with a minor offense, and diagnosed with a psychotic disorder and significantly less likely to be charged with a violent crime and to have substance use disorders than are competent defendants.

Competency Restoration

In light of the Supreme Court’s decision in Jackson (discussed above), most jurisdictions now require evaluators to provide an opinion regarding the restorability of a defendant who is considered incompetent to stand trial. In general, evaluators are usually required to provide information to the court on whether the defendant can be restored to competency (or the probability of restoration occurring) and what the available treatment options are for the defendant. In addition, some jurisdictions require the evaluator to provide an estimate of the time frame required for restoration. Generally, many defendants are restored to competency within 6 months, and the vast majority are restored within a 1-year period.

Although a full discussion of competency restoration is beyond the scope of this research paper, some research has examined the characteristics of restorable and nonrestorable incompetent defendants. In general, this research has indicated that those defendants considered to be restorable tend to be younger and are more likely to have a previous criminal history and a nonpsychotic diagnosis than their unrestorable counterparts.


  1. Dusky v. United States, 362 U.S. 402 (1960).
  2. Godinez v. Moran, 509, U.S. 389 (1993).
  3. Grisso, T. (2003). Evaluating competencies: Forensic assessments and instruments (2nd ed.). New York: Kluwer Academic/Plenum.
  4. Jackson v. Indiana, 406 U.S. 715 (1972).
  5. Melton, G. B., Petrila, J., Poythress, N. G., & Slogobin, C. (1997). Psychological valuations for the courts: A handbook for mental health professionals and lawyers (2nd ed.). New York: Guilford Press.
  6. Riggins v. Nevada, 504 U.S. 127 (1992).
  7. Roesch, R., & Golding, S. L. (1980). Competency to stand trial. Chicago: University of Illinois Press.
  8. Roesch, R., Zapf, P. A., Golding, S. L., & Skeem, J. L. (1999). Defining and assessing competency to stand trial. In A. K. Hess & I. B Weiner (Eds.), The handbook of forensic psychology (2nd ed., pp. 327-349). New York: Wiley.
  9. Sell v. United States, 539 U.S. 166 (2003).
  10. Washington v. Harper, 494 U.S. 210 (1990).
  11. Zapf, P. A., & Roesch, R. (2006). Competency to stand trial: A guide for evaluators. In I. B. Weiner & A. K. Hess (Eds.), The handbook of forensic psychology (3rd ed., pp. 305-331). New York: Wiley.
  12. Zapf, P. A., Viljoen, J. L., Whittemore, K. E., Poythress, N. G., & Roesch, R. (2002). Competency: Past, present, and future. In J. R. P. Ogloff (Ed.), Taking psychology and lawinto the twenty first century (pp. 171-198). Kluwer Academic/Plenum.

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