A current debate is whether actuarial risk assessment tools predict sexual recidivism in sexual offenders with intellectual disabilities (SOIDs). Since intellectual functioning exists on a spectrum, the present study examined the predictive validity of the Static-99R across the range of intellectual functioning. The sample was comprised of 454 adult sexual offenders assessed at an outpatient clinic and followed for an average of 10 years. Offenders in the extremely low/borderline group had higher scores on the Static-99R than other offenders, largely due to their score on the detachment subscale of the Static-99R, but did not have significantly higher recidivism rates. Calibration analyses suggested that the expected and observed recidivism rates did not differ significantly. Intellectual functioning did not add incremental validity to the Static-99R. Further, there was no interaction between intellectual functioning and actuarial risk score. The results suggested that the Static-99R can be used across the range of intellectual functioning, albeit somewhat more cautiously for those at the lowest and highest end of the intellectual functioning distribution.

Skye Stephens, Jennifer E. Newman, James M. Cantor & Michael C. Seto
Journal of Sexual Aggression: An international, interdisciplinary forum for research, theory and practice, 28 Sep 2017