In 2018 the Philadelphia District Attorney’s Office (DAO) created a new unit to track criminal justice measures on a consistent and ongoing basis: the District Attorney’s Transparency Analytics (DATA) Lab. They make the metrics readily available to the public, and evaluate their effectiveness to create and revise policies to ensure public safety. Unique among prosecutor offices in the US and globally, the DATA Lab undertakes original research, works as a partner with universities, and collects and analyzes data to inform policies, procedures, and progress. Follow the DA’s Office on Twitter @philadao.