The Contribution of Age to the Static-99 Risk Assessment in a Population-Based Prison Sample of Sexual Offenders

The Static-99 is the actuarial risk assessment instrument most commonly used and best validated for sexual offenders. Some research has indicated that the original version of the instrument does not sufficiently cover the influence of age-related decreases in recidivism risk of sexual offenders. Therefore, an age-corrected version, the Static-99R, has been proposed. It includes four age categories compared with only two in the original instrument. The purpose of this study was to examine the influence of several age-related variables on the predictive accuracy of the German version of the Static-99 using a population-based sample of prison-released sexual offenders (N = 1,077). The results indicated that—for the prediction of sexual reoffenses in a population-based prison sample—the original Static-99 performed better than the age-corrected Static-99R. Theoretical and empirical implications for research as well as recommendations for applied risk assessment settings are discussed.