NADD Bulletin Volume IV Number 3 Article 3

Complete listing

Systematic Treatment of Criminal Offenders Having Developmental Delay

Marc Goldman, M.S.


Reiss and Szyszko (1983) demonstrated that clinicians often fail to see beyond an individual’s disability. Those responsible for providing care/support tend to explain aberrant behavior as characteristic of all individuals having developmental disabilities. The unfortunate consequence of such limited conceptualization is lack of treatment. The individual might be subjected to punitive consequences for his or her behavior. Medications might be prescribed. Such attempts to eliminate undesirable behavior often results in failure. The individual is viewed as treatment resistant and frequently experiences long-term restrictions of freedom.

Similar tendencies have been informally observed when faced with developing supports for individuals who have broken the law. In such cases however, it appears that service providers often fail to see the person convicted, or accused of a crime, beyond the anxiety inducing label: criminal offender. Mikkelsen and Stelk (1999) observed that psychiatrists and human service professionals lacking experience with offenders having developmental disabilities perceive such individuals as, “someone to be feared; highly dangerous; untreatable; cannot be safely managed in a community-based setting.” Comprehensive understanding of the individual, their social setting, and their interaction with the criminal justice system, is necessary to reduce the potential for recidivism.


While most estimates of incarcerated individuals having developmental disabilities range from 2%-12%, others are considerably higher (Noble & Conley, 1992). Under and over identification of prisoners having developmental disabilities has been attributed to the use of group assessments, poorly trained examiners, failure to evaluate adaptive skills, the emotional state of the examinee at the time of testing, and cultural bias. Based on data from Departments of Corrections that administered the Wechsler Adult Intelligence Test-Revised, Noble and Conley (1992) concluded that approximately 2% of the prison population in the United States is comprised of individuals having developmental disabilities. This estimate does not include those individuals residing in local or county jails, those remanded to residential treatment facilities as a result of criminal (or alleged) criminal behavior, or those on probation or parole. Brown and Stein (1997) found that many criminal acts are not reported to authorities. They discovered about one-third of observed agencies investigated reports of sexual abuse by a consumer of services without involving additional agencies (including legal authorities).

Individuals with developmental disabilities appear to be over represented within the population of sex offenders (Day, 1993; Santamour, 1986). A study of 2,536 individuals referred for forensic evaluation found the rate for sex offense charges of developmentally delayed defendants almost twice as high as defendants having normal intelligence (Hawk, Rosenfeld, & Warren, 1993). Day (1993) found that between 12% and 46% of developmentally disabled offender populations were comprised of those convicted of sex offences as compared to 0.9% in the general population. Although such statistics should be interpreted as a call to action, they should not be viewed as confirming past beliefs that people having developmental disabilities are sexually dangerous (Hingsburger & Tough, 1998). In some cases, people with developmental disabilities and criminal charges are guilty only of violating agency policy rather than criminal statute.

Vulnerability to the Criminal Justice System

Upon their first encounter with police, people having developmental delay are likely to communicate and behave in ways that increase the possibility of arrest and punishment (Perske, 1991). It is unlikely that they understand their constitutional rights to an attorney or that police are entitled to employ devious methods in order to obtain confessions. Motivation to hide their disability as well as a need to please others can lead to false confessions and incarceration. Adjustment to prison has been observed to be poor. Smith, Algozzine, Schmid, and Henly (1990) found that prisoners having developmental disabilities were 2-3 times more likely to receive “disciplinary reports” than matched convicts who were not disabled.

Vulnerability to Criminal Behavior

Criminal behavior may be the result of multiple underlying variables. Explanation of criminal behavior has progressed from the belief that such behavior was the result of “feeblemindedness” to an emphasis on personality and social stresses (Douglas, Burgess, Burgess, & Ressler, 1992; Noble & Conley, 1992). People having developmental disabilities are a heterogeneous population (Seghorn & Ball, 2000). Although it has been argued that that they commit crimes for the same multifaceted reasons as those of normal cognitive abilities, Garner, Graeber, and Machkovitz (1998) noted that such factors as unemployment, the tendency to follow others, poor judgement, impulsivity, emotional problems, need for money, and criminal lifestyle are risk or “vulnerability” factors for criminal behavior.

Inappropriate sexual behavior can be the result of one or more vulnerabilities. Griffiths, Quinsey, and Hingsburger (1989) argued that abnormal sexual development might be the consequence of numerous system influences. An abnormal learning environment, community segregation, restrictive and punitive sexual policies, lack of privacy, lack of sexual education and responsibility training, poor partner selection, and societal attitudes, might combine or individually influence abnormal sexual behavior. They maintained that modification of sexual misbehavior can generally occur through implementation of positive teaching and counseling techniques but they noted that individuals engaging in paraphilic behaviors (i.e. deviant arousal) would require additional interventions.


Evaluation of a criminal offender having mental retardation should include close examination of individual, social, and system characteristics (Gardner, Graeber, & Machkovitz, 1998; McGee & Menolascino, 1992). Numerous intervention needs will be the likely result. The following suggestions should be considered as examples of some issues to be considered rather than a comprehensive list.

 The individual’s personal characteristics should be thoroughly examined. Personal characteristics that increase vulnerability or likelihood to commit crimes should be reviewed. Does the individual have a mental illness? Are symptoms florid when criminal activity occurs? Is the offender under the influence of drugs or alcohol when the crime is committed? Do other personal or social/environmental “destabilizing” factors increase the likelihood of criminal acts? Does the offender have a sense of personal responsibility? Is he or she lonely, thus likely to follow the lead of others? Has the offender engaged in crimes as a result of encouragement of others? Does the person have a strong need to please authority and likely to admit to crimes not committed?

Intervention requirements are often deduced from an understanding of historical information. It is essential to know what learning and social conditions shaped the individual. Current conditions should also be reviewed. Does the individual have the opportunity and/or skills to meet desired goals without breaking the law? Does the offender have skill deficits such as poor social skills or decision-making abilities? Were such skill deficits a factor in the offensive act? The context under which criminal behavior occurs is very important (Mikkelsen & Stelk, 1999). Assessment of context may reveal patterns and necessary precursors to criminal behavior. Assessment of context might reveal that the individual has only violated agency policy rather than criminal law. Review of police reports often leads to a clearer understanding of what took place. It may be determined that the actual charge does not reflect the seriousness or inconsequential nature of the offense.

Assessment of risk for future criminal behavior and security needs should be evaluated concurrently. The above suggestions will facilitate determining risk and security needs. In addition, accurate assessment of severity, frequency, and latency of criminal acts are required (Mikkelsen & Stelk, 1999). Failure to provide adequate security measures, despite appropriate treatment interventions, is likely to result in recidivism.


People having developmental delay are vulnerable within the criminal justice system due to both internal and external influences. Not only do many individuals have characteristics that set them up for criminal behavior but also they are also likely to interact with police, lawyers, and courts in a manner resulting in unfortunate outcomes. Treatment should be based on intervention needs discerned from careful evaluation of personal, social, and system vulnerabilities. Individuals having developmental disabilities that have engaged in criminal acts are entitled to assessment and treatment as are their non-offending peers. Service providers will need to look beyond the label of criminal offender in order to meet their multiple treatment needs.


Brown, H. & Stein, J. (1997) Sexual abuse perpetrated by men with intellectual disabilities: A comparative study. Journal of Intellectual Disability Research, 41, 215-224.

Day, D. (1993). Crime and mental retardation: A review. In K. Howells and C. R. Holland (Eds.), Clinical approaches to the mentally disordered offender (pp. 111-144). Chichester: John Wylie & Sons, Ltd.

Douglas, J. E., Burgess, A. W., Burgess, A. G., & Ressler, R. K. (1992). Crime classification manual: A standard system for investigating and classifying violent crimes. San Francisco: Jossey-Bass.

Gardner, W. I., Graeber, J. L., & Machkovitz, S. J. (1998). Treatment of offenders with mental retardation. In R.M. Wettstein (Ed.), Treatment of offenders with mental disorders (pp. 329-364). New York: The Guilford Press.

Griffiths, D., Quinsey, Q. & Hingsburger, D. (1989). Changing inappropriate sexual behavior: A community based approach for persons with developmental disabilities. Baltimore, MD: Paul H. Brookes.

Hawk, L. G., Rosenfeld, B. D., & Warren, D. S. W. (1993). prevalence of sexual offenses among mentally retarded criminal defendants. Hospital and Community Psychiatry, 44, 784-786.

Hingsburger, D. & Tough, S. (1998). Hey!! Watch your mouth! The NADD Bulletin, 1, 95-97.

McGee J. J. & Menolascino F. J. (1992). The evaluation of defendant with mental retardation in the criminal justice system. In R.W. Conley, R. Luckasson, & G. N. Bouthilet (Eds.), The criminal justice system and mental retardation: Defendants and victims (pp. 55-77). Baltimore: Brookes.

Mikkelson, E. J. & Stelk, W. J. (1999). Criminal offenders with mental retardation: Risk assessment and the continuum of community-based treatment programs. Kingston, NY: NADD Press.

Noble, J. H., & Conley, R. W. (1992). Toward an epidemiology of relevant attributes. In R. W. Conley, R. Luckasson, & G. N. Bouthilet (Eds.), The criminal justice system and mental retardation: Defendants and victims (pp. 17-53). Baltimore: Brookes.

Perske, R. (1991). Unequal Justice. Nashville: Abingdon Press.

Reiss, S., & Szyszko, J. (1983) Emotional disturbance and mental retardation: Diagnostic overshadowing. American Journal of Mental Deficiency, 87, 396-402.

Santamour, M., B. (1986). The offender with mental retardation. Prison Journal, 66, 3-18.

Seghorn, T. K. & Ball, C. J. (2000). Assessment of sexual deviance in adults with developmental disabilities. Mental Health Aspects of Developmental Disabilities, 3, 47-53.

Smith, C., Algozzine, B., Schmid, R., & Hennly, T. (1990). Prison adjustment of youthful inmates with mental retardation. Mental Retardation, 28, 177-181.

For further information:

Marc Goldman, M.S.
2310 Snowcrest Trail
Durham, NC 27707