Prosecuting attorneys enjoy broader discretion in making decisions that influence criminal case outcomes than any other actors in the American justice system. That they do so with little or no public scrutiny suggests questions about justice and fairness. This study examines the impact of legal, quasi-legal, and extra-legal factors on case outcomes throughout the prosecutorial process. It then examines how prosecutors weigh these factors in their decision making and explores the formal and informal mechanisms that constrain or regulate prosecutors decision-making. The study examines case screening decisions, charging decisions, plea offers, sentence recommendations, and dismissals in two moderately large county prosecutors offices. It includes statistical analyses of actual case outcomes, responses to a standardized set of hypothetical cases, and responses to a survey of prosecutors opinions and priorities, as well as qualitative analyses of two waves of individual interviews and focus groups.