Static-99R: Strengths, Limitations, Predictive Accuracy Meta-Analysis, and Legal Admissibility Review

Most risk assessment scales are developed to broadly rank individuals according to their risk to reoffend, not to inform particular legal decisions. Consequently, there is almost always a gap between what the scale measures and the referral question. The present article discusses the most commonly used and researched risk assessment tool for individuals charged or convicted of sexual offenses: Static-99R. This review summarizes relevant history, and psychometric, applied, and legal admissibility information for those who use the scale or encounter its use in court. The first section outlines the development, purpose, and evolution of Static-99R. The second section summarizes interrater reliability and predictive validity. We conducted an updated meta-analysis of 56 studies, whereby Static-99R demonstrated moderate predictive accuracy (AUCs = .68 to .69). The third section discusses field issues. Last, we summarize the tool's admissibility across 85 legal cases, of which four resulted in inadmissibility and an additional 12 in partial admissibility. We provide suggestions for cross-examination in court. We outline how Static-99R meets Daubert criteria for legal admissibility. Although Static-99R has important limitations, we conclude that it can be useful and informative in legal decisions (caveats discussed) and is demonstrably better than the alternate of not using structured risk scales.

Automated summary

Most risk assessment scales are developed to broadly rank individuals according to their risk to reoffend, not to inform particular legal decisions. This article focuses on Static-99R, the most commonly used and researched risk assessment tool for individuals charged or convicted of sexual offenses. It provides an overview of the scale's development, reliability, validity, and legal admissibility. Despite its limitations, Static-99R is shown to be useful in legal decision-making and better than not using structured risk scales.