Simulations of Judicial Pretrial Decisions to Explore Risk Assessment Validation

Abstract

The pretrial phase in criminal cases is critical in determining the trajectory of a defendant’s case, particularly during the first appearance hearing when a judge decides whether to release or detain the defendant. Traditionally, judges made these decisions at their own discretion, but in recent years, data-driven risk assessment tools have emerged to guide these judgments. This thesis builds upon the growing body of research exploring the effectiveness of such tools, specifically focusing on the Public Safety Assessment, a widely-used pretrial risk assessment tool. Drawing from data sets from randomized controlled trials conducted by the Access to Justice Lab at Harvard Law School, I developed simulation code to explore the effects of risk assessment tools on judicial decisions and pretrial outcomes. This work provides researchers with a unique approach that uses simulations to examine how unobserved factors and missing data can influence the assumptions underlying risk assessment models.