Intellectual Ability and Sexual Recidivism Risk Assessment: Comparing Predictive Accuracy in an Incarcerated U.S. Sample

Abstract

While studies indicate that individuals with intellectual disabilities (ID) and borderline intellectual functioning (BIF) are overrepresented among those incarcerated for sexual offenses, there is a paucity of research with respect to risk assessment for this population, particularly among incarcerated U.S. samples. This gap is concerning given that individuals perceived as high risk may be denied bail, given harsher sentences, or subject to civil confinement. The present study examined the predictive validity of the Static-99 and Static-99R, which rely on historical predictors, and the MnSOST-R, which includes a dynamic subscale. Archival records were used to compare individuals with ( n = 459) and without ( n = 459) ID/BIF released from New Jersey state prisons between 1996 and 2007, with an average follow-up period of 5.7 years. All three instruments demonstrated good predictive validity for those without ID/BIF, while only the MnSOST-R produced a significant AUC value for those with ID/BIF. Reincarceration rates for those with ID/BIF within high-risk groups ranged from 0% to 8%, similar to the overall recidivism base rate of 4%. Results highlight the need for additional research to determine which risk factors should be considered for those with ID/BIF.