Forensic Competency to Stand Trial Assessment Tools


An important aspect of the adjudication process in the criminal justice system of the United States is that all the defendants must be accorded a fair trial (Weiner, Goldstein, & Otto, 2012) and (Pirelli, Gottdiener, & Zapf, 2011). The concept of mental competency as a prerequisite for trial process was established in the judicial system by the Supreme Court’s Dusky decision of 1960 (Pirelli, Gottdiener, & Zapf, 2011). Since then, a psycholegal concept known as Competency to Stand Trial (CST) was introduced. The CST process is done among the criminal justice victims to assure that they are fit and competent to stand criminal trials and respond sufficiently to charges leveled against them.

Competency to Stand Trial Evaluation Tests and Screening Instruments

The jurisdictions to issue for a Competency to Stand Trial evaluation can be issued by the prosecution, the judiciary or the defense, at the preverdict phase of the criminal trial process (Weiner, Goldstein, & Otto, 2012). When victims are referred, the Mental Health Professionals, such as psychiatrists, while taking into consideration the ethical responsibilities, must conduct assessments using the CST tests and instruments. Numerous Competency to Stand Trial tests and tools are available for use by the Forensic Mental Health Professionals. The following are some of the CST tests and screening instruments that would assist a forensic mental health professional in conducting a CST evaluation.

Read also Criminal Trial Procedural Steps

Fitness Interview Test (FIT)

Developed in 1984 by Roesch, Webster, and Eaves, the FIT is a Canadian fitness to stand trial test, which uses a semi-structured interview (Stafford & Sellbom, 2012). The test contains items, which are focused on the legal issues and the assessment of the psychopathology. The test has since been revised and the current revised version is referred to as the Fitness Interview Test – Revised (FIT-R). The test uses a scoring system, which has since been changed to a three-point scale, with 0=serious impairment, 1=mild impairment and 3= No impairment.

The FIT-R test take approximately 30 minutes and consists of structured interviews that touches on knowledge of the criminal justice procedures, the ability to have a coherent knowledge on the consequences of the proceedings and the ability to participate or communicate with the counsel. The three aspects of the FIT-R are then broken into a number of questions that centers on the fitness to stand trial.


According to (Nussbaum, Hancock, Turner, Arrowood, & Melodick, 2007), although the FIT-R is a relatively new test, there are bodies of research that have tested the reliability of the instrument. For instance, a study carried among the nurses, physicians, forensic psychologists and graduate students of psychology; found that the screening process provides reliable evaluation of the ability to stand trial. In the study, the authors point that the overall interclass correlation was 0.98 for judgment fitness, with high reliability estimates among the professional groups.

Moreover, other recent studies that sought to identify assessment tools that were suitable for juveniles, evaluated the suitability of the FIT-R for the purpose (Nussbaum, Hancock, Turner, Arrowood, & Melodick, 2007).  The studies examined the reliability for sections, items and a determination of competence, compared to the interrater reliability of the clinical ratings to numerical summary scores. In addition, the structural validity of the FIT-R was determined using the confirmatory factor analysis to determine whether the FIT-R adhered to its 3-factor abilities. The studies concluded that the FIR-R provided satisfactory interrater reliability, with a relatively consistent structure factor when the tool was employed among the juvenile defendants. On the cognitive organization, it has been found that the FIT-R provides a high agreement between the FIT-R and MacCAT-CA scores.


Despite its ability for use as a screen, the FIT-R has some weaknesses for recommendation for its use. According to (Stafford & Sellbom, 2012), in a study to compare the legal abilities of defendants with psychotic disorders, mental illnesses, substance abuse disorders and affective disorders, some FIT-R sections did not rate 60% of the defendants as impaired. Furthermore, (Nussbaum, Hancock, Turner, Arrowood, & Melodick, 2007) notes for individuals who experience acute psychotic disorders, the rigor of the FIT-R interviews may surpass their focus and attention capacities. Also, the author asserts that partial administration may tap the attention capacities of the impaired individuals but fail to replicate the typical durations of the criminal trials.

(Nussbaum, Hancock, Turner, Arrowood, & Melodick, 2007) further observes that operationally, FIT-R provides a general description of the capacities under consideration, while listing questions to probe the knowledge of the accused. According to the authors, objectivity and rigor to the assessments relating to the elicited responses are not provided for in the FIT-R.

The MacArthur Competence Assessment Tool – Criminal Adjudication

The MacArthur Competence Assessment Tool was developed in 1988 from the more extensive MacArthur Structured Assessment of the Competencies of Criminal Defendants, by Otto and colleagues (Stafford & Sellbom, 2012). According to the authors, the MacArthur Competence Assessment Tool – Criminal Adjudication is an abbreviated clinical version of the (MacSAC-CD). The instrument assesses the three abilities of understanding, reasoning and appreciation.

MacArthur Competence Assessment Tool – Criminal Adjudication consists of 22 items, which take approximately 30 minutes to administer. The first eight items assesses the understanding of the legal system. The understanding of the defendant is assessed and if found questionable, the information is disclosed and the understanding further assessed. The next eight items assess the ability to learn the disclosed information, while the final six items assess the appreciation of one’s circumstances.

Strengths & Weaknesses

The main strength of the MacCAT-CA stems from its focus on the measure of the defendants ability to learn and make appropriate decisions (Stafford & Sellbom, 2012). In addition, MacCAT-CA possesses high internal consistency. These are explicit in its high Cronbach’s alpha values for understanding, reasoning and appreciation (Nussbaum, Hancock, Turner, Arrowood, & Melodick, 2007). However, according to the authors, the major weakness of the assessment tool arises from its less effectiveness in the identification of the presumed incompetent persons. According to the authors, MacCAT-CA is less effective compared to a combined consideration of the historical and clinical status predictors and the rigorous states that the CA was intended to measure. In addition, it does not include measures of response style, which means the possibility of feigning must be assessed using other assessment tools.

Competency Screening Tests (CST)

The CST is a sentence completion screening tests (tool), consisting of 22 items. The screening tool was developed by Lipsit, Lelos, and McGarry in 1971, and is mostly used in the initial screening process. The tool employs a scoring strategy, with the scores ranging from 2 = competent to answer, to 0= incompetent to answer.

Strengths and Weaknesses

The available research studies have reported an interrater reliability of 0.88-0.95 and a classification accuracy of 71-84%. Moreover, the tool is associated with higher internal consistency. However, the tool has been criticized for its major weaknesses. The tool offers an extremely positive view of the legal process. In addition, the CST has tendencies to produce false positives, labeling the competent defendants as incompetent and incompetent as competent.

Competence Assessment for Standing Trial with Mental Retardation (CAST-MR)

The CAST-MR is employed to assess the competence to stand trial for individuals with intellectual disabilities, based on Dusky criteria. It consists of three scales, where two consists of Basic Legal Concepts and Skills to Assist the Defense, which are based in theoretical situations that the defendant and his/her attorney are likely to face (Stafford & Sellbom, 2012). The third scale consists of the Understanding Case Events, which are open-ended questions that tap into the understanding of the events in the defendants own court case.

Strengths and Weaknesses

According to (Stafford & Sellbom, 2012), the initial validity and reliability studies that were carried among the home residents with retardation, the normal defendants and defendants with mental retardation but not referred, referred defendants send for Competency to Stand Trial , have all produced high levels of internal consistency. The defendants that the studies considered competent has significantly higher scores as measured on the Wechsler Adult Intelligence Scale–Revised (WAIS-R) (mean IQ 66) than those with an IQ of 57, who were considered incompetent. However, the authors point that persons with mental retardation can lower their scores on CAST-MR, when instructed to do so. This offers a great weakness for the assessment tool, making it hard to use in case of malingering defendants.

Sullivan’s Case: A CST Case Study

            Sullivan was a 32-year old pool store attendant charged with murder, arson and burglary. He was mentally retarded and had IQ scores of 65-68. His attorney thought that he might have been retarded to be competent to stand a trial and referred him to a psychologist. 

The Interview Transcript

Psychologist: What will your lawyer do if you have a case trial?

Sullivan: Show the jury that I’m innocent.

Psychologist: How could he best do that?

Sullivan: Ask some questions and have me tell them that I would not hurt Ricky.  I loved Ricky.

Psychologist: What does the prosecutor do in your trial?

Sullivan: Try to get me to be found guilty.

Psychologist: Who decides if you are guilty or not?

Sullivan r: The jury

Evaluation of Sullivan’s Competency

            Although the mental retardation limited the ability of Sullivan to understand the trial proceedings, he understands the nature of charges against him and their general purposes. Therefore he can assist his attorney, and is competent to stand trial.

Read also Case Analysis – The Casey Anthony / Caylee Anthony Trial

The Ethical Responsibilities of the Forensic Mental Health Professional 

            It is the responsibility of the mental health professional to ensure they use the assessments instruments in an appropriate manner (Kalmbach & Lyons, 2006). According to the author, ethical responsibilities start with adequate preparation, which involves gathering of all information related to the case, mental health records of the defendant, seeking permission from his/her attorney and informing of the defendant of any limitations of the confidentiality of the assessment interview.

 Finally, there is need for the development of an understanding of the culturally influenced variability, norm groups and other psychometric properties. In addition, the forensic mental health professional must exercise integrity, avoid conflict of interests and ensure they exercise impartiality and fairness.

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