Applicability of the New Static-99 Experience Tables in Sexually Violent Predator Risk Assessments

The Static-99 is an actuarial risk assessment tool often used in the evaluation of sexually violent predators. The risk estimates from the original Static-99 developmental sample ( experience tables”; Hanson & Thornton, 2000) have been criticized as being inaccurate when applied to contemporary groups of sexual offenders including sexually violent predators. In response to these concerns, the Static-99 developers released revised experience tables based on a large combined sample of 6,406 sexual offenders that now replace the data from the original Static-99 (Hanson & Thornton, 2000). These risk data have been touted as more reliable and representative of sexual offenders in general and sexually violent predators in particular (Harris et al., 2008). This article uses basic psychometric and test construction principles to examine the reliability and validity of new Static-99 experience tables and the proposed interpretation rules as utilized in applied risk assessments with sexually violent predators when determining the legal standard for sexual recidivism. Recommendations for application of the new risk estimates are discussed.