Field Validity of Static-99/R Scores in a Statewide Sample of 34,687 Convicted Sexual Offenders
The Static-99 (and revision, the Static-99R) reflect the most researched and widely used approach to sex offender risk assessment. Because the measure is so widely applied in jurisdictions beyond those on which it was developed, it becomes crucial to examine its field validity and the degree to which published norms and recidivism rates apply to other jurisdictions. We present a new and greatly expanded field study of the predictive validity (M = 5.23 years follow-up) of the Static-99 as applied system-wide in Texas (N = 34,687). Results revealed stronger predictive validity than a prior Texas field study, especially among offenders scored after the release of an updated scoring manual in 2003 (AUC = .66 to .67, d = .65 to .69), when field reliability was also stronger. But calibration analyses revealed that the Static-99R routine sample norms led to a significant overestimation of risk in Texas, especially for offenders with scores ranging from 1 to 5. We used logistic regression to develop local Texas recidivism norms (with confidence intervals) for Static-99R scores. Overall, findings highlight the importance of revisiting and updating field study findings, and the potential benefits of using statewide data to develop local norms.