NADD Bulletin Volume VII Number 3 Article 2

Complete listing

Using the CAST-MR with Juvenile Offenders with Mental Retardation

Charlotte M. Kimmel, Ph.D; Nedra H. Francis, M.A.; Spindletop MHMR ServicesBeaumont, Texas

This study was conducted to determine the validity of using the CAST-MR (Competence Assessment for Standing Trial for Defendants with Mental Retardation) instrument with juvenile offenders to determine their competency to stand trial or fitness to proceed and to begin establishing norms for juvenile offenders with mental retardation. The CAST-MR was normed primarily on adult offenders with mental retardation, but is frequently used to determine competency of juvenile offenders with mental retardation. Twenty-one male juvenile offenders were administered a comprehensive forensic court-ordered evaluation that included the CAST-MR to determine their level of functioning and competency to continue with the judicial process. These preliminary results suggest that the CAST-MR does have validity for determining the competency of male juvenile offenders with mental retardation. Additional juveniles need to be administered the CAST-MR to determine the generalizability of the results of this study to others.

The "Options for Justice" program began with a mission to hold offenders with developmental disabilities responsible for their actions, while at the same time advocating for fair and equitable treatment for them (Linhorst, 2002). An analysis of Texas criminal procedures concerned with seriously mentally impaired individuals reveals that upon deinstitutionalization of state psychiatric and other hospitals " community resources did not keep pace with the needs of the &ldots; population (persons diagnosed with mental illness and/or mental retardation), leaving a significant population of mentally impaired clients with unmet residential and service needs". Furthermore, a study conducted in the Dallas County jail reported that at least "15% of the inmate population were or had been clients of an MH/MR (community mental health/mental retardation) system" (Shannon & Benson, 1999). Many individuals commit crimes and enter the criminal justice system due to these unmet needs.

Title II of the Americans with Disabilities Act (ADA) of 1992 prohibits state and local governments from discriminating against an individual with a disability (The ARC, 2003a, b). The Association of Retarded Citizens (ARC) has published a brochure to assist police officers when they come in contact with persons who have a diagnosis of mental retardation. This brochure provides the police officer with information about persons diagnosed with mental retardation and mental illness. Communication and behavioral cues are given that may assist in identifying these persons. Simple tips are also included so appropriate information can be obtained from the individual. Most law enforcement, prosecutorial, judicial and corrections officials have not been provided adequate information and training about mental retardation. In 1990, a report was completed by the Hogg Foundation for mental health, which emphasized the need for law enforcement personnel to become more knowledgeable and understanding of persons with mental illness (Shannon & Benson, 1999)

The ARC has identified strategies to ensure compliance with American with Disabilities Act (ADA) principles. One of these strategies deals with "Determining Competency to Stand Trial". In essence, it states that whenever there is "good faith doubt" about the defendant's competency, an evaluation should be conducted by a psychologist to determine the level of functioning of the defendant based on a formally accepted diagnostic definition of mental retardation. The psychologist should have expertise in mental retardation, forensics, and court experience. In addition, it is recommended that an instrument, such as the Competence Assessment for Standing Trial for Defendants with Mental Retardation (CAST-MR) be used to help determine competency of a person with mental retardation.

It is necessary for a person to demonstrate competency in regards to legal and criminal proceedings in order to protect the rights of the individual and ensure due process. If there is a question about individual competency, the courts require an examination to establish competency. In regards to juveniles, the Texas Family Code has been revised to address proceedings concerning competency. Section 55.31(a) Unfitness to Proceed Determination reads as follows:

"A child alleged by petition or found to have engaged in delinquent conduct or conduct indicating a need for supervision who as a result of mental illness or mental retardation lacks capacity to understand the proceedings in juvenile court or to assist in the child's own defense is unfit to proceed and shall not be subjected to discretionary transfer to the criminal court, adjudication, or modification of disposition as long as such incapacity endures."

(Shannon & Benson, 1999).

The CAST-MR is the first validated instrument designed to provide information on competence to stand trial in adult defendants with mental retardation (Everington & Luckasson, 1992). A competency evaluation is based on the Supreme Court case Dusky v. United States (1960) and the American Bar Association Criminal Justice Mental Health Standards (1984), which defines and expounds on the definition of competency. These definitions indicate that:

"the test for determining mental competence to stand trial should be whether the defendant has sufficient present ability to consult with the defendant's lawyer with a reasonable degree of rational understanding and otherwise to assist in the defense, and whether the defendant has a rational as well as factional understanding of the proceedings."

The CAST-MR was developed to assist in determining competency of individuals with mental retardation (Smith, 2000). Research suggests this instrument demonstrates strong internal consistency, validity and inter-rater reliability (Everington & Dunn, 1995). This is the only competency-screening instrument developed specifically for individuals diagnosed with mental retardation. Persons with mental retardation may have particular vulnerabilities that can impair their competency. The ARC states individuals with mental retardation may not demonstrate competency in the following areas:

"to stand trial - due to difficulty understanding judicial proceedings, inability to understand charges, inability to assist counsel.

"to confess - inability to understand Miranda warnings, vulnerability to pressure during interrogation, inability to give an accurate and reliable confession, overly eager to please authority figures by confessing.

"to plead guilty - inability to understand legal terms and/or consequences of their actions, may plead guilty without understanding why and doing so for approval.

Investigators have shown that acquiescence (defined in psychometric literature as the tendency to agree with or say yes to statements or questions, regardless of the content of items) is negatively correlated to cognitive abilities (Finlay, 2002). This means that persons with mental retardation are particularly likely to respond "yes" to any question presented to them. When consulting with an attorney, language deficits and limited comprehension may contribute to an inadequate ability to assist in their own defense. Individuals with a diagnosis of mental retardation may have deficits in cognition with regard to decision-making, social understanding and moral reasoning (Conley, Luckasson, & Bouthilet, 1992).

These vulnerabilities may also apply to adolescents, particularly adolescents with mental retardation. It might be expected that juveniles would be afforded increased assistance in assuring that they understand the proceedings in which they are about to engage. Near the end of the 19th century, juveniles were separated from adult offenders in the prison system due to the assumption that adolescents had different cognitive capacities and needs than adults (Ashford, Sales, & Reid, 2001). However, the courts currently appear to assume that juveniles are fit to proceed, just as adults are assumed to be competent (Dinerstein & Buescher, 1992). Juveniles are typically screened to determine if they may have a lack of responsibility for their conduct due to mental illness or mental retardation (Texas Family Code, Chapter 55). If this screening reveals an atypical result, the juvenile may be referred for a comprehensive assessment to determine their fitness to proceed with the legal process. There are no known assessment instruments specifically designed to determine fitness to proceed for adolescents with mental retardation.

Some courts may certify juveniles as adults for trial and reject the claims of those juveniles alleging "mental disability" (Mental and Physical Disability Law Reporter, 1987). There is considerable concern with the concept of competency to stand trial in the juvenile courts (Heilbrun, Hawk, & Tate, 1996), but few instruments designed for this specific purpose. Thomas Grisso has done considerable work on completing forensic evaluations with juvenile offenders (Cruise, 2001) and developed a model Miranda statement to determine comprehension of these rights (Baroff, 1996), but this work is not specific to juvenile offenders with mental retardation.

Since 1976, there have been approximately 43 individuals diagnosed with mental retardation that has been executed (Keyes, Edwards, & Perske, 1997). The data indicate the possibility of more people being included in this number due to the lack of assessments or referrals for evaluation that may have been ignored or never discovered. This type of information should be symbolic of the extensive need to adequately assess the competency level of all persons with mental retardation in the court system, particularly juveniles. The need for an instrument to adequately assess this population is evident. While the CAST-MR appears to adequately assess competency for adults with mental retardation, very few adolescents were included in the initial norm group (Everington & Luckasson, 1992). This study was conducted to determine the appropriateness of using the CAST-MR with juveniles offenders diagnosed with mental retardation.


Juvenile offenders were referred by the courts to a local Community MHMR Center for a comprehensive assessment by a doctoral level psychologist to determine their level of functioning and competency. The CAST-MR (Competence Assessment for Standing Trial for Defendants with mental Retardation) was administered as part of this assessment.

All juvenile offenders receive an initial psychological screening during their incarceration in juvenile detention. This initial screening usually consists of an abbreviated intelligence test such as the Wechsler Abbreviated Scale of Intelligence (WASI), an educational screening using an instrument such as the Wide Range Achievement Test-Revision 3, and a personality inventory such as the Millon Adolescent Clinical Inventory.

If the results of the initial screening suggested functioning within the range of mental retardation, then the Juvenile Probation Officer generally will request an order from the presiding judge for a court ordered forensic evaluation from the Community MHMR Center to determine the appropriateness of a diagnosis of mental retardation and eligibility for mental retardation services. The competency of the juvenile offender was also assessed to determine the ability to understand basic legal concepts, the ability to assist with his own defense, and the understanding of his own case. The results of the comprehensive evaluation, including a diagnostic interview and a review of other school and medical records, assist in the determination of competency. The CAST-MR was the assessment tool used to assist in evaluating the competency of these juvenile offenders.


This study includes the results of a comprehensive evaluation of 26 juveniles ranging in ages from 12-17. Each juvenile had been charged with a crime and had served time in a juvenile detention center. The crimes allegedly committed by the juveniles included burglary, assault, running away, and destroying public property. None of the juveniles had been charged with murder. All of the juveniles are African American males. Refer to Table I for complete demographic data.


The majority of the juveniles were in detention at the time of their court-ordered forensic comprehensive assessment. Generally, their Juvenile Probation Officer transported these juveniles in shackles and handcuffs to the Community MHMR Center. Occasionally, the juvenile had been released from detention and was living with family members in the community. In that situation, a family member (usually the mother) provided transportation to the Center for the evaluation. Occasionally, the Juvenile Probation Officer provided the transportation even for those juveniles who were living in the community. The mother was usually present during the initial interview to provide background, early developmental history, and social information including the skills, abilities, and problems of their child in the home. If the mother or other family member was not present, the above information would be obtained via a phone conversation with an appropriate family member.

The assessment was completed in 2 to 4 sessions depending on the cooperativeness and attention span of the juvenile. During the initial session, a clinical interview was completed with the juvenile, probation officer, and family member, if available. Then, individual psychological testing was initiated. The CAST-MR would usually be administered during the final testing session.. Testing was generally completed within a one month time period.

The comprehensive assessment generally included the following instruments: a major intelligence test, typically the Wechsler Intelligence Scale for Children-III (WISC-III) or the Wechsler Adult Intelligence Scale-III (WAIS-III); the Peabody Picture Vocabulary Test-III (PPVT-III); the Bender Visual Motor Gestalt Test (BVGMT); the Vineland Adaptive Behavior Scales-Interview Edition, Survey Form (VABS); the Inventory for Client and Agency Planning (ICAP); the Kaufman Test of Educational Assessment, Brief form (KTEA); and the Competence Assessment for Standing Trial for Defendants with mental Retardation (CAST-MR).


The purpose of this study is to determine if the CAST-MR adequately assesses competency in juvenile offenders with mental retardation. A comparison was completed between the IQ scores from the initial adult norm group as described in the CAST-MR manual and the current group (see Table 2). This comparison reveals that there is no difference between the IQ scores of the competent adults (IQ=59) and the IQ scores of the competent juveniles (IQ =59). There is also no significant difference between the IQ scores of the incompetent adults (IQ=58) and the IQ scores of the incompetent juveniles (IQ =59).

In order to determine the validity of the CAST-MR with juvenile offenders, the means of the competent juveniles with mental retardation were compared with the means of competent adults with mental retardation as reported in the CAST-MR manual (Everington & Luckasson, 1992) in Table 3. The means of each section and total score were somewhat higher for the competent juveniles with mental retardation than the means for the competent adults with mental retardation, with the exception of Section II, which measures the ability to assist in their own defense. The Section II mean score for juveniles was slightly lower (9.71) than the mean score for adults (10.7). This similarity in results suggest that the CAST-MR does measure competency for juvenile offenders with mental retardation.

In Table 4, the means of the incompetent juveniles with mental retardation were compared with the means of incompetent adults with mental retardation. This data indicates that the juveniles were more likely to understand their case events (8.57) when compared to adults (5.2) as identified by Section III of the CAST-MR.

A Pearson Correlation was completed on the data collected for the juvenile norm group in this study. The results of this correlation study reveal that there is a significant positive correlation between the CAST-MR Total Score and the following assessments: IQ as measured by the Wechsler instruments (.72), Vineland Adaptive Behavior Scales-VABS (.73), Street Survival Skills Questionnaire-SSSQ (.80), Kaufman Test of Educational Achievement-KTEA (.79), and the Kaufman Test of Educational Achievement: Reading subtest-KTEA-R (.80). As these results reveal, the best predictors of competency on the CAST-MR appear to be the results of the SSSQ, KTEA, and the KTEA-R. The lowest correlation occurred between the ICAP and the CAST-MR total score (.60).


As the demographic information shows there is considerable similarity between the initial adult offender norm group and the current juvenile offender population, particularly in regards to the IQ of the two groups. When the means for the competent adults are compared to the means of the competent juveniles, the juvenile scores appear somewhat higher. This result was not expected because it was hypothesized that juveniles would have similar or lower scores based strictly on their age and experience. Perhaps the difference in scores might be explained because the juveniles have increased exposure to environmental influences including interaction with other juvenile offenders, in other words the juveniles appear to be "street smart". Adult offenders with mental retardation are more likely to be segregated from the general adult offender population. Juveniles, as a group, are more likely to be protected, but not from each other.

This hypothesis is further substantiated by the results of the Pearson Correlation coefficient. The SSSQ is highly correlated (.80) with the CAST-MR total score suggesting that street survival skills knowledge is an important variable in achieving competency. Street knowledge appears to be more important than overall adaptive behavior functioning. Level of adaptive behavior functioning, as measured by the Vineland (.73) and the ICAP (.60), is not as highly correlated with competency. This difference appears likely because the Vineland and ICAP include an emotional or behavioral component in the total score that appears to lower the adaptive behavior score. It can be expected that any population of juvenile offenders is likely to include youth who have emotional and behavioral problems. The SSSQ does not include this behavioral component; the score is strictly based on knowledge of street skills and adaptive behaviors. Juvenile offenders frequently may have the knowledge, but they may choose not to use this knowledge to comply with requests of authority figures including teachers and parents. For example, this means that the juveniles may know how to complete chores and other tasks, but they choose not to do them. The ICAP and Vineland instruments measure actual task performance, while the SSSQ measures task knowledge and identification skills.

In addition to the SSSQ, the KTEA-Reading subtest (.80) and the KTEA-total score (.79) also demonstrates the same high level of correlation. Academic achievement, including the ability to read, learn, acquire, and retain knowledge, appears to be a good indicator of competency. This result might be expected.

In summary, it appears that the CAST-MR can be used with juvenile offenders with mental retardation. This study suggests that the CAST-MR appears valid for determining competency of juvenile offenders with mental retardation as it is for determining competency of adult offenders with mental retardation when their cognitive skills are measured at a similar level of functioning according to the results of a standardized cognitive instrument such as a Wechsler intelligence scale. Although the number in this sample group was similar in size to the initial norm group. Further studies with additional groups of juvenile offenders with mental retardation are recommended for generalization of the results.


Ashford, J. B., Sales, B. D., & Reid, W. H. (2001). Political, legal, and professional challenges to treating offenders with special needs. In J. B. Ashford, B. D. Sales, & W. H. Reid (Eds.), Treating adult and juvenile offenders with special needs. Washington, DC: American Psychological Association.

Baroff, G. S. (1996). The mentally retarded offender. In J. W. Jacobson & J. A. Mulick (Eds.), Manual of Diagnosis and Professional Practice in Mental Retardation (pp.311-321). Washington, DC: American Psychological Association.

Conley, R. W., Luckasson, R., & Bouthilet, G. N. (1992). The criminal justice system and mental retardation. Baltimore: Brooks.

Cruise, K. R. (2001). The mentally ill juvenile offender. In Forensic Psychology Workshop (pp. 1-7). Huntsville, TX: Sam Houston State University.

Dinerstein, R. D. & Buescher, M. (1992). Capacity and the courts. In R. D. Dinerstein, S. S. Herr, & J. L. O'Sullivan (Eds.), A guide to consent (pp.95-109). Washington, DC: American Association on Mental Retardation.

Everington, C. & Dunn, C. (1995). A second validation study of the competence assessment for standing trial for defendants with mental retardation (CAST-MR). Criminal Justice & Behavior, 22, 44 -59.

Everington, C. & Luckasson, R. (1992). Competence Assessment for Standing Trial for Defendants with Mental Retardation (CAST-MR). Worthington, OH: IDS Publishing.

Finlay, W. M. L., & Lyons, E. (2002). Acquiescence in interviews with people who have mental retardation. Mental Retardation, 40, 14-29.

Heilbrun, K., Hawk, G. & Tate, D. C. (1996). Juvenile competence to stand trial: Research issues in practice. Law & Human Behavior, 20, 573-578.

Keyes, D., Edwards, W., & Perske, R. (1997). People with mental retardation are dying, legally: At least 44 have been executed. Mental Retardation, 40 , 243-244.

Linhorst, D. M, Bennett, L., & McCutchen, T. (2002). Development and implementation of a program for offenders with developmental disabilities. Mental Retardation, 40, 41-50.

Mentally disabled criminal defendants (1987). Mental & Physical Disability Law Reporter, 11, 180-181.

Shannon, B. D. & Benson, D. H. (1999). Texas criminal procedure & the offender with mental illness: A analysis and guide (2nd ed.) Austin: NAMI-Texas (National Alliance for the Mentally Ill).

Smith, S. (2000). Barriers to being, becoming and remaining competent to stand trial. NADD Bulletin. 3 , 3-5.

The ARC. (2003a). A police officer's guide when in contact with people who have mental retardation. [Brochure]

The ARC. (2003b). When people with mental retardation go to court. [Brochure].