Skip to content

Sexual Offenders with Intellectual Disabilities: A Brief Overview

This article is from Volume 5, Issue 4 of Forensic Scholars Today, a quarterly publication featuring topics from the world of forensic mental health.

*The statements, views, and opinions in this article are the author’s. These statements are not the views or opinions of WA DOC or the WA DOC SOTAP.

This article will provide a brief overview of the literature related to male sexual offenders with intellectual disabilities. Sexual offenders with intellectual disabilities present a unique challenge to correctional and criminal justice professionals for a variety of reasons. Of concern, individuals with intellectual disabilities may go undetected (Marotta, 2015) and can spend many years incarcerated before someone realizes an incarcerated individual has an intellectual disability. In addition, it is not uncommon for this population to have deficits or responsivity needs that make it difficult for them to understand what is being told to them, they may not be able to read or write, or they may misinterpret cues. Furthermore, their behaviors should not be overlooked, and a multidisciplinary approach may be needed for this population. As a result, it is important criminal justice and treatment professionals take the time to understand the needs of sexual offenders with intellectual disabilities, to include adapted treatment approaches.

Key Points to Know

For those interacting with sexual offenders with intellectual disabilities, it is important to consider competency, suggestibility, and interview challenges that may arise. In certain situations, sexual offenders with intellectual disabilities may be more likely to give unreliable or misleading information (Murphy, 2016). In addition, criminal justice professionals should be cautious when working with this population as they are more prone to suggestibility, acquiescence, and responding in ways that please the interviewer (as cited in Clare & Gudjonsson, 1993) which could pose some challenges for those who are doing the questioning or interviewing (Cohen & Harvey, 2016). This may also pose a challenge not only for treatment providers, but for correctional officers and police officers who interview someone with an intellectual disability and it is essential that all criminal justice professionals be trained to have some understanding of how sexual offenders with intellectual disabilities may present during questioning or interviews. Based on the research, it is important to consider how competency and suggestibility impact this population. Clearly, there is a need for criminal justice professionals to be concerned with potential competency issues as this population is often at a disadvantage as they try to navigate their way through the criminal justice system (Lindsay, 2002).

Moreover, it is concerning that professionals working with individuals with an intellectual disability may be minimizing offending behaviors, and in some cases, criminal behavior may not be reported to law enforcement (Steans & Duff, 2018). Criminal justice professionals should not enable or minimize behavior and should reach out to sex offender treatment providers or other experts to consult about behaviors so that they can be addressed appropriately. More importantly, “the behaviors of the developmentally disabled sexual offender population are not significantly different from the non-disabled offender population” (Blasingame, 2001, p. 46) and they should still be held accountable for their behaviors.


Cognitive Behavioral Therapy (CBT) is recommended for sexual offenders with intellectual disabilities; however, treatment programs should be adapted to be the most effective (Jones & Chaplin, 2017). This population will have deficits in intellectual and adaptive functioning (American Psychiatric Association, 2013). As a result, an individual with an intellectual disability will have difficulties with abstract concepts, planning, problem solving, making plans, and communicating (American Psychiatric Association, 2013). Due to the challenges of working with this population, Marotta (2017) discussed the importance of being responsive to the psychosocial needs and risk or relapse for this population and that sex offender treatment programs are taking into consideration the cognitive, emotional, and behavioral challenges that sexual offenders with intellectual disabilities have.

It is recommended that sex offender treatment programs adhere to the Risk-Need-Responsivity model (as cited in Andrews & Bonta, 2010) which can help clinicians target dynamic risk factors (Cohen & Harvey, 2016). Treatment approaches that include role-play, skits, collages, and drawing may be useful to help convey treatment concepts (Blasingame, 2001). Cohen and Harvey (2016) looked at CBT-based treatments for sexual offenders with learning deficits where treatment was adapted to meet the needs of this population and found that the treatment program incorporated a sexual knowledge piece, interventions were taught at a slower pace and over a longer period of time, and that repetition and creativity were also utilized. Lindsay (2002; Jones & Chaplin, 2017) points out that that there may be better treatment outcomes for sexual offenders with an intellectual disability if they are in treatment for a minimum of two years.


Intellectual testing and risk assessments have been used in forensic settings for sexual offenders with an intellectual disability. While many states conduct assessments on incarcerated persons to see if they have an intellectual disability, methods of assessment are not consistent (Lindsay, 2002). Even within institutional settings, assessments vary among clinicians which may need to be examined further to glean whether or not this has any impact on treatment or resources. Risk assessment tools can be used to assess recidivism risk for sexual offenders with intellectual disabilities (as cited in Hanson et al., 2013; Stephens, Newman, Cantor, & Seto, 2018; Delforterie, van den Berg, Bolt, van den Hazel, Craig, & Didden, 2019). Some of the risk assessments commonly used to assess risk include the STATIC-99R and the STABLE-2007.

The STATIC-99R is an actuarial risk assessment tool that can be used with this population but should be used cautiously depending on the level of intellectual functioning (Stephens et al., 2018). The STABLE-2007 is an empirically validated risk assessment tool that is also used in both the United States and Canada to assess risk among sexual offenders (Hanson, Helmus, & Harris, 2015). Although there are other risk assessment tools used with this population, only the STATIC-99R and the STABLE-2007 will be discussed in this article.

Research highlights that sexual offenders with an intellectual disability may be more similar to those without an intellectual disability as they both have cognitive and behavioral deficits, and both have cognitive distortions (Keeling, Beech, & Rose, 2007). When sexual offenders with intellectual disabilities were compared to sexual offenders without an intellectual disability (mild or borderline) there were not significant difference between the two groups for the ten static items on the STATIC-99R (Delforterie et al., 2019). On the other hand, when the two groups were compared on the STABLE-2007, there was a significant difference on the dynamic risk factors; sexual offenders with an intellectual disability showed more problems in the domain lack of concern for others, impulsive acts, and poor problem solving (Delforterie et al., 2019). Notably, there was no significant difference between the two groups on nine of the risk factor domains, such as emotional identification with children, capacity for relationship stability, or significant social influences; Delforterie et al. (2019) explain there are few differences between individuals who committed a sex offense with or without an intellectual disability.


Some of the literature points out that sexual offenders with intellectual disabilities commit sexual crimes at a higher rate when compared to sexual offenders without intellectual disabilities (Blasingame, 2016). Marotta (2017) also notes that individuals with intellectual disabilities have a high rate of recidivism (as cited by Camilleri & Quinsey, 2011; Heaton & Murphy, 2013; Klimecki, Jenkinson, & Wilson, 1994; Lambrick & Glaser, 2004; Lindsay, Elliot, & Astell, 2004; Polaschek, 2003) which supports the need for increased awareness, research, and training about sexual offenders with intellectual disabilities. Notably, recidivism rates have been reported as high as 43% in this population (Marotta, 2017; as cited by Lindsay, Steptoe, Wallace, Haut, & Brewster, 2013).

Final Thoughts

In order for criminal justice and forensic professionals to address the needs of this population, it is clear that a multidisciplinary approach is needed. Furthermore, training staff is essential, so they are aware of how risk factors present in this population and take precautions when interviewing and questioning sexual offenders with intellectual disabilities. Given that recidivism rates are higher among this population, treatment programs should be open to adapting their program to help reduce sexual recidivism.

Author Biography:

Amanda (Mandy) Fenrich is a Ph.D. Candidate and currently completing her degree in the advanced studies of human behavior through Capella University. Mandy obtained her Master of Arts in Human Services with an emphasis in forensic mental health and her Bachelor of Criminal Justice from Concordia University, St. Paul in St. Paul, Minnesota. Mandy is currently employed as a psychology associate for the Washington State Department of Corrections’ Sex Offender Treatment and Assessment Program (SOTAP). She provides sex offender treatment to individuals at the Special Offender Unit (SOU), a residential treatment unit for individuals with serious mental illness. She also has experience providing treatment to sex offenders with intellectual disabilities and is one of the authors creating an adapted sex offender treatment manual for this population. Her previous experience includes working as a community corrections officer, where she supervised offenders in the Special Needs Unit with various mental health needs. She is an ad-hoc reviewer and publishes on a variety of criminal justice and forensic mental health topics.


  1. American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Washington, DC: Author.
  2. Andrews, D. A., & Bonta, J. (2010). The psychology of criminal conduct (5th ed.). London: Routledge.
  3. Blasingame, G.D. (2001). Developmentally disabled persons with sexual behavior problems. Treatment, management & supervision. Oklahoma City, OK: Wood ‘N’ Barnes Publishing.
  4. Blasingame G.D. (2016) Assessment, diagnosis, and risk management of sexual offenders with intellectual disabilities. In: Phenix A., Hoberman H. (eds) Sexual Offending. New York, NY: Springer.
  5. Camilleri, J. A., & Quinsey, V. L. (2011). Appraising the risk of sexual and violent recidivism among intellectually disabled offenders. Psychology, Crime & Law, 17, 59-74.
  6. Clare, I. C. H., & Gudjonsson, G. H. (1993). Interrogative suggestibility, confabulation, and acquiescence in people with mild learning disabilities (mental handicap): Implications for reliability during police interrogations. British Journal of Clinical Psychology, 32(3), 295–301.
  7. Cohen, G., & Harvey, J. (2016). The use of psychological interventions for adult male sex offenders with a learning disability: a systematic review. Journal of Sexual Aggression, 22(22), 206-223.
  8. Delforterie, M., van den Berg, J., Bolt, B., van den Hazel, T., Craig, L. & Didden, R. (2019). Comparing STATIC-99R and STABLE-2007 between persons with and without intellectual disabilities. Journal of Intellectual Disabilities and Offending Behaviour, 10(3), 58-68.
  9. Hanson, R. K., Helmus, L. M., & Harris, A. J. (2015). Assessing the risk and needs of supervised sexual offenders: A prospective study using STABLE-2007, Static-99R, and Static 2002R. Criminal Justice and Behavior, 42(12), 1205-1224.
  10. Hanson, R. K., Sheahan, C. L., & VanZuylen, H. (2013). STATIC-99 and RRASOR predict recidivism among developmentally delayed sexual offenders: A cumulative meta analysis. Sexual Offender Treatment, 8, 1–14.
  11. Heaton, K. M., & Murphy, G. H. (2013). Men with intellectual disabilities who have attended sex offender treatment groups: A follow-up. Journal of Applied Research in Intellectual Disabilities, 26, 489-500.
  12. Jones, E., & Chaplin, E. (2017). A systematic review of the effectiveness of psychological approaches in the treatment of sex offenders with intellectual disabilities. Journal of Applied Research in Intellectual Disabilities, 33(1), 79-100.
  13. Keeling, J. A., Beech, A. R., & Rose, J. L. (2007). Assessment of intellectually disabled sexual offenders: The current position. Aggression and Violent Behavior, 12(2), 229-241.
  14. Klimecki, M. R., Jenkinson, J., & Wilson, L. (1994). A study of recidivism among offenders with an intellectual disability. Australia and New Zealand Journal of Developmental Disabilities, 19, 209-219.
  15. Lambrick, F., & Glaser, W. (2004). Sex offenders with an intellectual disability. Sexual Abuse: A Journal of Research and Treatment, 16(4), 381-392.
  16. Lindsay, W.R. (2002). Research and literature on sex offenders with intellectual and developmental disabilities. Journal of Intellectual Disability Research, 46, 74-85.
  17. Lindsay, W. R., Elliot, S. F., & Astell, A. (2004). Predictors of sexual offence recidivism in offenders with intellectual disabilities. Journal of Applied Research in Intellectual Disabilities, 17, 299-305.
  18. Lindsay, W. R., Steptoe, L., Wallace, L., Haut, F., & Brewster, E. (2013). An evaluation and 20- year follow-up of a community forensic intellectual disability service. Criminal Behaviour and Mental Health, 23, 138-149.
  19. Marotta, P. L. (2017). A systematic review of behavioral health interventions for sex offenders with intellectual disabilities. Sexual Abuse, 29(2), 148-185.
  20. Murphy, Glynis H. (2016). Sexual relationships and adults with intellectual disabilities. In: Carr, A. and Linehan, C. and O’Reilly, G. and Noonon Walsh, P. and McEvoy, J., eds. Handbook of Intellectual Disability and Clinical Psychology Practice. London: Routledge.
  21. Polaschek, D. L. (2003). Relapse prevention, offense process models, and the treatment of sexual offenders. Professional Psychology: Research and Practice, 34, 361-367.
  22. Steans, J., & Duff, S. (2018). Perceptions of sex offenders with intellectual disability: A comparison of forensic staff and the general public. Journal of Applied Research in Intellectual Disabilities, 00, 1–9.
  23. Stephens, S., Newman, J. E., Cantor, J. M., & Seto, M. C. (2018). The Static-99R predicts sexual and violent recidivism for individuals with low intellectual functioning. Journal of Sexual Aggression, 24(1), 1-11.