Risk assessment in offenders with intellectual disability: the evidence base

The Structured Assessment of Violence Risk in Adults with Intellectual Disability: A Systematic Review

BACKGROUND

While structured professional judgement approaches to assessing and managing the risk of violence have been extensively examined in mental health/forensic settings, the application of the findings to people with an intellectual disability is less extensively researched and reviewed. This review aimed to assess whether risk assessment tools have adequate predictive validity for violence in adults with an intellectual disability.

METHODS

Standard systematic review methodology was used to identify and synthesize appropriate studies.

RESULTS

A total of 14 studies were identified as meeting the inclusion criteria. These studies assessed the predictive validity of 18 different risk assessment tools, mainly in forensic settings. All studies concluded that the tools assessed were successful in predicting violence. Studies were generally of a high quality.

CONCLUSIONS

There is good quality evidence that risk assessment tools are valid for people with intellectual disability who offend but further research is required to validate tools for use with people with intellectual disability who offend.

The predictive validity of common risk assessment tools in men with intellectual disabilities and problematic sexual behaviors

This CIHR-funded study examined whether certain current risk assessment tools were effective in appraising risk of recidivism in a sample of sex offenders with intellectual disabilities (ID). Fifty men with ID who had engaged in problematic sexual behavior (PSB) were followed for an average of 2.5 years. Recidivism was defined and measured as any illegal or problematic behavior, as well as any problematic but not necessarily illegal behavior. At the beginning of the study, each participant was rated on two risk assessment tools: the Violence Risk Appraisal Guide (VRAG) and the Sex Offender Risk Appraisal Guide (SORAG). During each month of follow-up, participants were also rated on the Short-Dynamic Risk Scale (SDRS), an assessment tool intended to measure the risk of future problematic behaviors. Data was analyzed using t-tests, Cohen's d and area under the curve (AUC) to test predictive validity of the assessment tools. Using the AUC, results showed that the VRAG was predictive of sexual (AUC=0.74), sexual and/or violent (AUC=0.71) and of any criminally chargeable event (AUC=0.69). The SORAG was only significantly predictive of sexual events (AUC=0.70) and the SDRS was predictive of violent events (AUC=0.71). The t-test and Cohen's d analyses, which are less robust to deviations from the assumptions of normal and continuous distribution than AUC, did not yield significant results in each category, and therefore, while the results of this study suggest that the VRAG and the SORAG may be effective tools in measuring the short term risk of sexual recidivism; and the VRAG and SDRS may be effective tools in appraising long term risk of sexual and/or violent recidivism in this population, it should be used with caution. Regardless of the assessment tool used, risk assessments should take into account the differences between sex offenders with and without ID to ensure effective measurement.

Differences between juvenile offenders with and without intellectual disabilities in the importance of static and dynamic risk factors for recidivism

BACKGROUND

Juvenile offenders with intellectual disability (ID) have been largely ignored in the literature of risk assessment, while they are overrepresented in the criminal justice system, and ID is a risk factor for juvenile delinquency and recidivism. The aim of this study was to examine whether there are differences between juvenile offenders with and without ID in the impact of risk factors for recidivism. Both the impact of static and dynamic risk factors were examined. Static risk factors were examined in the criminal history domain and dynamic risk factors were examined in the domains of family, school, use of free time, friends, alcohol/drugs, attitude, aggression and skills. This knowledge is important for both assessment and treatment of juvenile offenders with ID.

METHOD

The sample consisted of adolescents who appeared before the courts for a criminal act and for whom the Washington State Juvenile Court Assessment (WSJCA) was completed. The group of ID juvenile offenders (n = 102) consisted of juvenile offenders with a formal diagnosis of ID, which means a full scale IQ of less than 70, coupled with significant deficits in adaptive behaviour, with childhood onset. The juveniles of this group are special education students or they have a formal diagnosis of a special education need. The group without ID (n = 526), was a random sample of all juvenile offenders without a formal diagnosis of ID.

RESULTS

No differences were found between juvenile offenders with and without ID in the impact of risk factors on recidivism in most domains. However, in the skills domain, the relations between all risk factors and recidivism were significantly stronger in adolescents without ID than in adolescents with ID. Although not or only borderline statistically significant, these risk factors were all negatively related to recidivism in adolescents with ID, whereas these risk factors were significantly and positively related to recidivism in adolescents without ID.

CONCLUSIONS

There are few differences between juvenile offenders with and without ID in the impact of risk factors for recidivism, suggesting that the same assessment methods can be used for juvenile offenders with and without ID. There were, however, differences between juvenile offenders with and without ID in the skills domain. What these differences mean for the treatment of juvenile offenders is yet to be determined. For now it is important to be aware of potential negative (side) effects on recidivism when skills training is offered to juvenile offenders with ID.

Recognising, assessing and managing offending behaviour in persons with intellectual disability

The association between intellectual disability and offending is complex. Recent evidence would suggest that the received wisdom of intellectually disabled persons being more prone to offending is either incorrect or only tells part of the story. Those within the ‘borderline’ intellectual disability range may be more prone to committing sexual and criminal damage offences but those with an IQ less than 50 rarely offend.

The offender with intellectual disability shares characteristics with his counterpart from the general population. As with the general population as a whole, offending in this group is often unreported and its recognition is complicated by issues of competence. The lack of validated forensic assessment schedules for this population poses a further challenge. Some general approaches to assessment in this population are discussed. This case report illustrates the difficulties of assessing and managing offending behaviour in an individual with moderate intellectual disability. The challenge of treating offenders with an intellectual disability is immense and requires specialist expertise. Managing such cases in a generic setting is inappropriate and the need for a forensic learning disability service in Ireland is highlighted.

Managing risk: a qualitative study of community-based professionals working with learning-disabled sex offenders

This study reports on research conducted to examine how community practitioners manage the difficulties of risk assessment in relation to people with a learning disability and a history of sexually offensive or abusive behaviour. Semi-structured interviews were conducted with a number of key professionals from various disciplines, all currently involved in the assessment process with the aim of determining potential referral to community settings. Data analysis revolved around a thematic exposition of factors influencing the relationship between the objective science of psychiatric investigation and the subjective interpretation of real-world practicalities in working with this group. Findings surrounded three major themes, frame conflict, relating to the difficulties of decision making in this area, therapeutic performance, whereby professionals were expected to engage in some form of active intervention, and safety outcomes, involving consideration of the problematic nature of judging the likelihood of re-offending.

Forensic learning disability nursing skills and competencies: a study of forensic and non-forensic nurses

This paper reports on an investigation into the skills and competencies of forensic learning disability nurses in the United Kingdom. The two sample populations were forensic learning disability nurses from the high, medium, and low secure psychiatric services and non-forensic learning disability nurses from generic services. An information gathering schedule was used to collect the data; of 1200 schedules, 643 were returned for a response rate of 53.5%. The data identified the "top ten" problems that forensic learning disability nurses may encounter, the skills and competencies necessary to overcome them, and the areas that need to be developed in the future. The results indicated that the forensic learning disability nurses tended to focus on the physical aspects to the role whilst the non-forensic learning disability nurses tended to perceive the forensic role in relational terms. This has implications for practice, policy, and procedures.

Persons with intellectual disabilities in the criminal justice system: review of issues

Although the vast majority of individuals with intellectual disabilities (ID) are law-abiding citizens, there is a small percentage with offending behaviour that is considered antisocial, socially inappropriate, or defined as illegal. It has long been recognised that individuals with ID or mental-health needs who break the law should be dealt with differently from the general population. There have been an increasing number of empirical studies in this area; however, these have been plagued by various definitional and methodological issues. Prevalence estimates of offenders with ID are complicated by diagnostic variations and inconsistencies in the criminal justice process. International studies have shown a large range, from 2% to 40%, depending on methodological approaches. The following review will highlight the salient issues including prevalence of offending, characteristics of offenders, vulnerabilities within the legal system, assessment, and a brief overview of intervention and treatment approaches.

Client-Centered Care for Individuals with Dual Diagnoses in the Justice System

1. The characteristics of people with developmental disabilities, such as poor judgment, low frustration tolerance, lack of impulse control, and naivete, compounded by the symptoms of a mental illness, contribute to their susceptibility to engage in problematic or criminal behaviors. 2. Nurses should recognize that conducting risk assessments for this population may take time and could involve modifying risk assessments to the individuals' abilities. 3. Providing appropriate care for this vulnerable population requires a long-term, interdisciplinary approach and quality community support services