This workshop arose out of the efforts of the Committee on Law and Justice to assist the National Institute of Justice in identifying gaps in the overall research portfolio on crime and justice. It was designed to develop ideas about the kinds of knowledge needed to gain a better understanding of the prosecution function and to discuss the past and future role of social science in advancing our understanding of modern prosecution practice. The Committee on Law and Justice was able to bring together senior scholars who have been working on this subject as well as current or former chief prosecutors, judges, and senior officials from the U.S. Department of Justice to share their perspectives. Workshop participants mapped out basic data needs, discussed the need to know more about recent innovations such as community prosecution, and discussed areas where one would expect to see changes that have not occurred. The resulting report summarizes these discussions and makes useful suggestions for learning more about prosecution.