This evaluation was developed and implemented by the Los Angeles District Attorney's Office to examine the effectiveness of specialized prosecutorial activities in dealing with the local problem of rising gang violence, in particular the special gang prosecution unit Operation Hardcore. One part of the evaluation was a system performance analysis. The purposes of this system performance analysis were (1) to describe the problems of gang violence in Los Angeles and the ways that incidents of gang violence were handled by the Los Angeles criminal justice system, and (2) to document the activities of Operation Hardcore and its effect on the criminal justice system's handling of the cases prosecuted by that unit. Computer-generated listings from the Los Angeles District Attorney's Office of all individuals referred for prosecution by local police agencies were used to identify those individuals who were subsequently prosecuted by the District Attorney. Data from working files on all cases prosecuted, including copies of police, court, and criminal history records as well as information on case prosecution, were used to describe criminal justice handling. Information from several supplementary sources was also included, such as the automated Prosecutors Management Information System (PROMIS) maintained by the District Attorney's Office, and court records from the Superior Court of California in Los Angeles County, the local felony court.