After describing the magnitude of the problem, the police are analyzed in terms of their role in influencing what happens after arrest. Three major aspects of this role are studied: factors pertaining to the arrest (tangible evidence, witnesses, and the time span between the offense and the arrest), the officer who makes the arrest, and the legal and institutional framework within which the arrest is processed. The findings, which show that the police have a major role in determining the outcome of the case in court, are discussed in terms of their implications for changes in police policy regarding rewards and incentives, training, and other aspects of police operations. The central policy implication is that the police can make a greater contribution to the criminal justice system by expanding their perspective of their own role from that of making arrests to that of making good arrests. Adopting such a perspective is likely to lead to improvement in specific areas, including training, promotion and incentive programs, and placement policies. Exhibits, chapter notes, and a subject index