Investigating Cash Bail Patterns in Pennsylvania

A key component of pretrial justice reform has been to overhaul the cash bail system, which has been known to unfairly and disproportionately affect poor communities of color. The lack of clear standards and the variability in decision making by magistrate judges has resulted in a system that is inconsistent in determining who must pay cash bail as well as the amount of bail. Together with the lack of any metrics or transparency associated with this process, the problem has escalated. The American Civil Liberties Union (ACLU) has been at the forefront of this fight to reform the bail determination system. To support their efforts, we utilized a dataset containing all criminal offenses charged within the state of Pennsylvania in 2016-17 in order to derive analytical insights, and perform a series of statistical tests to evaluate and quantify biases in the bail determination system in Pennsylvania. In addition to this, we also developed a predictive model and utilised model interpretability tools to evaluate the factors affecting bail type assignment. One of the key focus areas of our work was the determination of racial bias, particularly between the defendants identified as Black and White in the court records. Through our work, we were able to develop a pipeline for identifying racial bias and conclusively establish that bail assignment patterns do vary across judges.