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Online-Issues » 2-2007 » Douglas P. Boer et al.

Contextualizing Risk in the Assessment of Intellectually Disabled Individuals

Douglas P. Boer1, Keith R. McVilly2 & Frank Lambrick3
1University of Waikato; 2RMIT University, Melbourne; 3Victorian Department of Human Services

[Sexual Offender Treatment, Volume 2 (2007), Issue 2]


In this article we examine the idea of expanding structured clinical judgement from primarily offender variables to a broader framework in which environmental (including staff) variables are given equal consideration in a comprehensive risk appraisal conducted for risk management purposes of intellectually disabled individuals. It is posited that only by contextualizing the individual’s risk within environmental variables can an accurate portrayal of current dynamic risk (and hence the management of that risk) be construed.

Key words: offenders, risk assessment, environmental risk, individual risk

Support people and other environmental variables are rarely identified explicitly in risk assessment instruments for adult offenders except in close relationship to the individual under examination. In this brief article we will expand on the usual risk-related environmental variables (e.g., employment, relationships, supervision compliance) to include items that when examined in isolation may seem unrelated to offender risk, but we believe may figure prominently in risk management of intellectually disabled1 (ID; also referred to as learning disabled, developmentally-delayed, or mentally retarded, depending on the country, context, or diagnostic framework) individuals. These items arguably apply to non-ID individuals with behavioral problems who may or may not be offenders; however we would argue that environmental variables are of even greater importance in assessing and managing risk in ID individuals.  Furthermore, we would also propose that the principles and strategies applied in risk assessment of offenders with ID could be readily adapted to provide an assessment framework for people with ID who, though not involved in the criminal justice system, exhibit behaviors labeled as challenging; i.e., "culturally abnormal behaviours of such an intensity, frequency or duration that the physical safety of the person or others is likely to be placed in serious jeopardy, or behaviour which is likely to seriously limit the use of, or result in the person being denied access to ordinary community facilities" (Emerson, 2001; p.3).

In the commonly used structured clinical guideline instruments such as the Historical-Clinical-Risk-20 (Webster, Douglas, Eaves, & Hart, 1997), the Sexual Violence Risk-20 (Boer, Hart, Kropp, & Webster, 1997), the Risk for Sexual Violence Protocol (Hart, Kropp, & Laws, 2003), and the Spousal Abuse Risk Assessment Guide (Kropp, Hart, Webster, & Eaves, 1995), the issue of environmental variables related to risk are primarily related to relationship problems, employment problems, assaultive behavior, and violations of supervision. Most of these variables require redefinition for application to ID individuals. For example, ID individuals may have non-intimate relationships of a supportive nature (e.g., friends, parents, siblings, support workers), but they do not commonly have intimate relationships that involve independent living with an intimate partner. Similarly, ID individuals may have scheduled activities including working in a sheltered workshop or a volunteer activity, but these are generally highly supervised activities in contrast to non-ID occupations or jobs. In addition, ID individuals may or may not be charged with offences in some situations (e.g., in residential care settings) for behaviors that would generally warrant a charge if done by a non-ID individual. For example, ID individuals commonly assault staff members or expose themselves while in residential care and often do not get charged for such behaviors. Indeed, such behaviors are commonly labeled “challenging” behaviors as opposed to “offending” behaviors and are thus seen as problems to manage as opposed to requiring legal intervention. Finally, ID individuals may have great difficulty responding to conditions of court-imposed supervision (if found fit to stand trial) without the help of personnel from support agencies assisting the offender in such cases to attend supervision sessions. 

In a forthcoming book chapter, Boer and Lindsay have provided further explication of the items of the HCR-20 and SVR-20 for application to ID offenders. Both the HCR-20 and SVR-20 have been shown to have predictive validity for non-sexually and sexually violent ID offenders respectively (e.g., Morissey, Hogue, Mooney, Allen, Johnston, Hollin, Lindsay, & Taylor, 2007; Lambrick, 2003). However, the elaboration of test items or the validation of such tests with ID offenders does not help in all cases because many ID individuals are not charged for their offending (or challenging) behavior and hence these instruments (indeed all commonly used risk assessment instruments, including all the actuarial tests) would be inapplicable. For the assessment of risk for ID individuals with actual charges or convictions for sexual offences we suggest that the literature supports the use of the SVR-20 in combination with an actuarial instrument for a convergent risk assessment (Boer, 2006). However, the SVR-20 and all relevant actuarial risk assessment instruments do not provide much in terms of ID-specific risk assessment or management information, whether for individuals charged with offences, or those who simply present challenging behaviors. Similarly we support the use of the HCR-20 and a relevant actuarial instrument for the risk assessment of non-sexually violent ID individuals, but again, these tests do not provide much information for ID-specific risk assessment or management. And, given that the raison d’être of risk assessment is presumably to inform risk management, clearly this is a short coming of current risk assessment methodologies particularly when applied to ID individuals.

Given the relative greater dependence of ID individuals on external structures and supports, we (Boer and colleagues) have been working on an instrument for Assessment of Risk and Manageability for Individuals with Developmental, Intellectual, or Learning Limitations who Offend (ARMIDILLO).  This instrument has a much wider scope than originally anticipated in an earlier article (Boer, Tough, & Haaven, 2004) and expands the environmental variables to include a wide range of issues (e.g., staff attitudes towards ID individuals, communication amongst supervisory staff, client knowledge by staff, supervision consistency, environmental consistency, victim availability and access, availability of intoxicants, social support changes, use of structured daily activity plans). It is our hope that by contextualizing risk for ID individuals (i.e., offenders and those with “challenging” behaviors alike) by the use of dynamic environmental variables along with dynamic client variables (e.g., compliance with supervision, sex knowledge, mental health problems, time management skills, substance use, relationship skills, coping ability, emotional management ability) we will not only assess risk more accurately, but we will also better inform risk management plans for the individual client.  This more wide ranging scope of assessment is consistent with the model of assessment proposed by the American Association on Mental Retardation [AAMR] (AAMR, 2002).  Even more importantly, it is consistent with the bio-psycho-social model of assessment, as adopted by the International Classification of Functioning Disability and Health [ICF] (World Health Organization, 2001).   

In an earlier article, Boer, Tough and Haaven (2004) outlined a total of nine staff and other environmental variables posited to have a dynamic relationship of either a stable or acute nature to risk and risk manageability by ID sex offenders. In the upcoming ARMIDILLO, these same items (and additional items) have been re-defined to include all ID individuals being assessed for risk and risk management purposes. The reason for this increased emphasis on environmental dynamic variables is that we view an individual’s ability to cope independently of staff and an otherwise supportive environment varies inversely with level of ID. We would argue, for example, that access to services is inversely related to risk for offensive behavior by individuals with higher levels of ID. Similarly, we would argue that all of the environmental variables in the ARMIDILLO can serve risk increasing or risk decreasing (i.e., protective) functions. For example, Lambrick (2003) identified the “informed monitoring ability of staff” as a protective factor. While we espouse Lambrick’s notion of well-informed, well-trained staff as a risk-reducing protective factor, we would argue that the opposite is true as well: poorly trained or poorly motivated staff will likely be a risk increasing factor.  In support of this, LaVigna, et al., 1994 emphasize the importance of including an assessment of staff factors (i.e., as mediator variables) when planning and evaluating supports for people with ID and challenging behaviour. For example, a situation where a staff member or members disregard an ID individual (e.g., an ID sex offender) who has the ability to escape could lead to the escape of or reoffence by the offender. In this situation, the offender’s risk did not change, but the risk presented by the environment did change. If the offender escaped or reoffended in that context, that behavior would be the result of the risk brought to the situation by the offender and the context variables that were present at the time.

In order to contextualize risk, we suggest that the risk posed by the environment (staff included) should be assessed separately from that posed by the individual. Then, the convergence of the risk posed by the two sets of variables is as the overall level of risk posed by the individual in the context of the environmental variables that comprise the individual’s current circumstances. Of course, the consideration of environmental, including staff, variables is not new to risk management of ID individuals (e.g., McVilly, 2002), but is a significant departure from the usual risk assessment strategies commonly used with adult offenders.  In the literature pertaining to the support of people with ID not adjudicated as offenders but assessed as exhibiting challenging behaviour, the influence and consequently the importance of assessing environmental factors, including staff, has long been recognized (Allen, 1999; Hastings & Brown, 2000).  However, the technology to conduct such assessment in a systematic, valid and reliable way has not yet been developed  The benefits of the approach proposed here includes the immediate identification of environmental features that are risk-increasing and therefore require remediation to reduce risk and perhaps become protective factors in a risk management plan. While this article has not focused on the client variables, the same would be true of such variables.

In summary, we suggest expanding structured clinical judgement from primarily offender variables to a broader framework in which environmental (including staff) variables are given equal consideration in a comprehensive appraisal of risk and risk manageability for ID individuals. It is our opinion that only by contextualizing the individual’s risk within environmental variables can an accurate portrayal of current dynamic risk (and hence the management of that risk) be construed.


  1. Allen, D. (1999). Mediator analysis: an overview of recent research on carers supporting people with intellectual disability and challenging behaviour. Journal of Intellectual Disability research, 43, 325-339.
  2. American Association on Mental Retardation [AAMR] (2002). Mental retardation: definition, classification and systems of support, 10th ed. Edited by Luckasson, R., Borthwick-Duffy, S., Buntinx, W., Craig, E., Coulter, Schalock, R., Snell, M., Spitalnick, D., Reeve, A., Spreat, S. & Tasse, M. Washington, DC: AAMR.
  3. Boer, D.P. (2006). Sexual offender risk assessment strategies: is there a convergence of opinion yet? Sexual Offender Treatment, 1, 1-4.
  4. Boer, D.P., Hart, S.D., Kropp, P.R., & Webster, C.D. (1997). Manual for the Sexual Violence Risk – 20: Professional guidelines for assessing risk of sexual violence. Vancouver, B.C.: The Mental Health, Law, and Policy Institute.
  5. Boer, D.P., Tough, S., & Haaven, J. (2004). Assessment of risk manageability of intellectually disabled sex offenders. Journal of Applied Research in Intellectual Disabilities, 17, 275-283.
  6. Emerson, E. (2001). Challenging Behaviour: analysis and intervention in people with severe intellectual disabilities, 2nd Edition. Cambridge, UK: Cambridge University Press.
  7. Hart, S.D., Kropp, P.R., Laws, D.R., Klaver, J., Logan, C., & Watt, K.A. (2003). The Risk for Sexual Violence Protocol (RSVP). Burnaby, British Columbia, Canada: The Mental Health, Law, and Policy Institute of Simon Fraser University.
  8. Hastings, R. & Brown, T. (2000). Functional assessment and challenging behaviours: some future directions. Journal of the Association for Persons with Severe Handicaps, 25, 229-240. 
  9. Kropp, P.R., Hart, S.D., Webster, C.D., & Eaves, D. (1995). Manual for the Spousal Assault Risk Assessment Guide (2nd edition). Vancouver, B.C., Canada: The British Columbia Institute on Family Violence.
  10. Lambrick, F. (2003). Issues surrounding the risk assessment of sexual offenders with an intellectual disability. Psychiatry, Psychology & Law, 10, 353-358.
  11. La Vignia, G., Willis, T., Shaull, J., Abedi, M. & Sweitzer, M. (1994). The periodic service review: a total quality assurance system for human services and education. Baltimore, USA: Paul H. Brooks.
  12. McVilly, K.R. (2002). Positive Behaviour Support for People with Intellectual Disability. Sydney, New South Wales, Australia: Australian Society for the Study of Intellectual Disability.
  13. Morissey, C., Hogue, T., Mooney, P., Allen, C., Johnston, S., Hollin, C., Lindsay, W.R., & Taylor, J.L. (2007). Predictive validity of the PCL-R in offenders with intellectual disability in a high secure hospital setting: institutional aggression. Journal of Forensic Psychiatry and Psychology, 18, 1-15.
  14. Webster, C.D., Douglas, K.S., Eaves, D., & Hart, S.D. (1997). HCR-20: Assessing Risk for Violence (version 2). Burnaby, British Columbia, Canada: The Mental Health, Law, and Policy Institute of Simon Fraser University.
  15. Wechsler, D. (1997). WAIS-III Wechsler Adult Intelligence Scale – 3rd Edition. New York: The Psychological Corporation.
  16. World Health Organisation [WHO] (2001). International Classification of
    Functioning Disability and Health, 10th edition. Geneva, Switzerland: Author.


1 In this article ID individuals are seen as those individuals with a full-scale IQ of less than 75.  This figure takes into account the standard error of measurement of most of the commonly used intelligence tests.  Parenthetically, we view the WAIS-III (Wechsler, 1997) as the “gold standard” for ID classification.

Author address

Douglas P. Boer
Associate Professor and Director of Clinical Psychology
Department of Psychology
The University of Waikato
Private Bag 3105
Hamilton, New Zealand
E-Mail Link




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