In the American criminal justice system, prosecuting attorneys arguably enjoy broader freedom to make significant decisions than any other system actor. Although prior research has identified a number of legal and extra-legal factors that affect the decisions prosecutors make, some potentially important factors have not been thoroughly studied, and most of the existing research has focused on identifying the factors that affect decisions, not on how and when prosecutors weigh these factors. This video interview is part of a two-year research project, funded by the National Institute of Justice, that seeks to identify and gauge the influence of legal, quasi-legal, and extra-legal factors on the decisions that criminal prosecutors make over the lifetime of a case. Measuring the impact of these decisions on case outcomes is expected to yield practical guidelines for system decision makers committed to the principled use of prosecutorial discretion. Project researchers are using surveys of prosecutors, hypothetical case vignettes, administrative data from actual cases, and a series of interviews and focus groups to understand the factors that influence five critical decisions prosecutors make in the processing of criminal cases: 1) whether to accept or reject a case at initial screening; 2) what charges to file; 3) whether to dismiss or amend charges after filing; 4) what charges to specify in formal plea offers; and 5) sentence recommendations. Researchers will pay special attention to whether prosecutors use and are influenced by different factors at different decision-making stages and whether they weigh factors differently depending on the decision being made. The findings will provide a factual basis for considering ways to promote the principled use of prosecutorial discretion.