The study is based on two sets of data. The first is a probability sample of 1,888 felony arrests representing the roughly 102,000 felony arrests made in 1971 in four of New York City's five boroughs. The cases were traced from arrest to disposition. The second source of data was a probability sample of 369 defendants arraigned on felony charges whose cases were disposed of during the period January - October 1973. In addition to collecting the basic disposition data on these cases, interviews were conducted with the major participants in the disposition of each case. Reasons for the decisions made were the focus. The data reported portray the structure of crime in New York City and the demographic profiles of the persons arrested. The main dimensions of the disposition process are also reported (the rates at which arrests result in prosecutions and the way these prosecutions are channeled into bargained guilty pleas and trials). The mechanisms guiding the dispositions are also discussed. Following the presentation of close-ups of some of the major crime categories and their disposition patterns, special problem areas in the law enforcement system are addressed, primarily police activities and the operation of the bail system. Findings indicate that police arrest rates are low, and court conviction rates are unsatisfactory; however, there appears to be no way that the criminal justice system can significantly increase either of these activities. The offenders tend to be male juveniles from the slums and ghettos of the city. The study concludes that the crime-reduction approach offering the greatest promise is early intervention in the lives of slum youth who show signs of maladjustment, particularly in the school environment. Tabular and graphic data, chapter footnotes, and an author index are provided.