In This Article Expand or collapse the "in this article" section Competency to Stand Trial

  • Introduction
  • General Overviews of Competency to Stand Trial
  • Overview of Competency to Stand Trial Research
  • Origins of Competency to Stand Trial and Key Legal Cases
  • Forensic Psychiatry and Competence to Stand Trial
  • A Functional and Contextual Approach to Defining and Assessing Competency
  • Conceptual Models for Competence to Stand Trial
  • Characteristics of Incompetent Defendants
  • Cognitive Functioning
  • Juvenile Competency to Stand Trial
  • Competency to Stand Trial Evaluators
  • Competency to Stand Trial Assessment
  • The Fitness Interview Test-Revised Edition (FIT-R)
  • The MacArthur Competence Assessment Tool—Criminal Adjudication
  • The Evaluation of Competency to Stand Trial—Revised
  • The Inventory of Legal Knowledge
  • The Competence Assessment for Standing Trial for Defendants with Mental Retardation
  • Competency to Stand Trial Restoration

Psychology Competency to Stand Trial
Patricia A. Zapf, Amanda Beltrani
  • LAST MODIFIED: 15 January 2019
  • DOI: 10.1093/obo/9780199828340-0229


A core principle of modern-day law is that all defendants maintain the right to a fair trial. A defendant must be able to factually and rationally understand and participate in a court process, the ability to do so deems the defendant competent. Competency is relevant through all stages of the criminal justice process from arrest through sentencing. This article describes research and scholarship related to competency to stand trial. Competency to stand trial is a doctrine of jurisprudence that requires criminal proceedings to be postponed if a defendant is unable to meaningfully participate in his or her defense on account of a mental disease or defect. The US law regarding trial competency was established in the 1960 US Supreme Court Case Dusky v. United States (cited under Origins of Competency to Stand Trial and Key Legal Cases), and currently all states use some variant of the Dusky standard, with the exact definition varying by jurisdiction. Competency evaluations are essential to ensure the protection of a defendant’s due process rights guaranteed by the US Constitution. Approximately sixty thousand defendants are evaluated for trial competency annually, making this the most common forensic issue evaluated. Ultimately, an individual’s competency is a legal issue and does not have a distinct or easily identifiable psychological correlate. However, judges’ rulings closely follow mental health professionals’ recommendations most of the time, highlighting the importance of forensic mental health evaluators understanding the reason for the referral, the concerns surrounding competency, and the specific demands of the case. Issues of competency may be raised at any point during the proceedings, and if a bona fide doubt exists regarding competency, the issue must be formally considered: thus requiring a forensic evaluation. A defendant’s competency is assessed based on his or her present ability to understand court proceedings, make educated legal decisions, conduct oneself in a manner appropriate for court, and contribute to the development and execution of one’s legal defense. Forensic evaluators are tasked with describing the degree of congruence or incongruence between the relevant jurisdictional competency standard and the defendant’s current abilities. To complete this task, forensic evaluators must maintain a combination of advanced clinical skills coupled with knowledge about the legal system, competency standards, and the proper interpretation of the data collected for the evaluation.

General Overviews of Competency to Stand Trial

In an effort to clarify concerns that may arise during legal proceedings, Melton, et al. 2017 provides a comprehensive analysis on an array of topics relevant to a wide net of forensic mental health professionals, including a chapter specific to competency. Grisso, et al. 1994 is a seminal study that systematically explores the pretrial forensic evaluation systems in the United States and describes several models that employ various outpatient approaches for obtaining evaluations. Grisso 2003 discusses forensic assessment instruments specifically developed for competency evaluation. Zapf and Roesch 2009 offers a detailed guide to assist forensic mental health professionals in conducting competency evaluations. Zapf and Roesch 2013 provides a concise overview of competency to stand trial for legal professionals, from defining competency to reviewing forensic assessment instruments related specifically to competency assessments. A detailed review of the assessment procedures that guide competency evaluations, the challenges faced, and an overview of the related law can be found in Stafford and Sellbom 2013 and Zapf and Roesch 2009. Finally, Otto, et al. 2014 reviews forensic mental health reports and effective testimony.

  • Grisso, T., J. J. Cocozza, H. J. Steadman, W. H. Fisher, and A. Greer. 1994. The organization of pretrial forensic evaluation services: A national profile. Law and Human Behavior 18:377–393.

    DOI: 10.1007/BF01499046

    This study surveyed forensic mental health professionals in the fifty US states and the District of Columbia. The aim was to describe state governmental services for providing pretrial, court-ordered mental health forensic evaluations of criminal defendants. Specifically inquiring about competence to stand trial and criminal responsibility evaluations. A five-type solution for categorizing the states’ system was developed and the nuances within these five general typologies are discussed.

  • Grisso, T. 2003. Evaluating competencies: Forensic assessments and instruments. 2d ed. New York: Kluwer.

    Offers a conceptual model to assist forensic mental health professionals to understand the nuances of legal competencies, improve assessment procedures, and guide research to advance the evaluation of legal competencies. A review of numerous instruments often used in different areas of legal competence is conducted.

  • Melton, G. B., J. Petrila, N. G. Poythress, et al. 2017. Psychological evaluations for the courts: A handbook for mental health professionals and lawyers. 4th ed. New York: Guilford.

    Provides a valuable guide to issues that the legal system commonly asks clinicians to address. This book is written for all forensic mental health professionals conducting psychological evaluations for the court and the legal professionals who request these evaluations. The authors provide a brief background of each topic, discuss pertinent research, and offer suggestions on effectively communicating evaluation findings to courts.

  • Stafford, K., and M. Sellbom. 2013. Assessment of competence to stand trial. In Handbook of psychology: Forensic psychology. 2d ed. Vol. 11. Edited by R. K. Otto and I. Weiner, 412–439. Hoboken, NJ: John Wiley.

    Issues related to the evaluation process such as the use of competence assessment instruments, report writing, and special populations are discussed. Highlights dispositional challenges, such as treatment of incompetent defendants, prediction of restorability, and dispositions in cases of permanently incompetent defendants.

  • Otto, R. K., R. L. DeMier, and M. T. Boccaccini. 2014. Forensic reports and testimony: A guide to effective communication for psychologists and psychiatrists. Hoboken, NJ: John Wiley.

    This chapter is aimed to assist forensic mental health professionals in providing strong, accurate, and effective reports and testimony. Distinguishes between general clinical and forensic report writing and details why these distinctions are critical. In addition, the article provides examples of reports, affidavits, and testimony of experts in the field, as well as comments and critiques.

  • Zapf, P. A., and R. Roesch. 2009. Best practices in forensic mental health assessment. Evaluation of competence to stand trial. New York: Oxford Univ. Press.

    A comprehensive discussion of the legal and conceptual issues involved in adjudicative competency evaluations. Reviews laws related to defendants’ competence to stand trial, related research, and methods of assessment to provide forensic psychologists with the foundational information necessary to conduct competency evaluations.

  • Zapf, P. A., and R. Roesch. 2013. Evaluation of competence to stand trial in adults. In Forensic assessments in criminal and civil law: A handbook for lawyers. Edited by R. Roesch, P. A. Zapf, R. Roesch, P. A. Zapf, 17–22. New York: Oxford Univ. Press.

    Presents material relevant to legal consumers, regarding the evaluation of competence to stand trial. The legal context for competency evaluations and relevant forensic mental health concepts are discussed. A review of the empirical foundations and limitations of competency evaluations, information about the evaluation method, the process of report writing, and testimony is provided.

  • Zapf, P. A., R. Roesch, and G. Pirelli. 2014. Assessing competency to stand trial. In The handbook of forensic psychology. 4th ed. Edited by I. B. Weiner, R. K. Otto, I. B. Weiner, R. K. Otto, 281–314. Hoboken, NJ: John Wiley.

    A detailed review of a portion of empirical research and writings on competence to stand trial is reviewed. Provides a brief overview of competency law, research, and assessment. Aims to provide forensic psychologists with the basic information necessary to conduct competency evaluations.

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