Recent research by the Center on Administration of Criminal Justice at the University of California examined case attrition in a Florida jurisdiction and in a California jurisdiction. The study involved detailed onsite observations in the jurisdictions and a statistical study of approximately 500 robbery, burglary, and felony assault cases in each jurisdiction. More limited observations were also conducted in seven other jurisdictions throughout the country. The study found that the most important determinant of conviction is arrest policy, and the second most important determinant of conviction is the amount of evidence in the case. The research concludes that both police and prosecutors should make more convictions their goal. Police resources should focus on arrest cases and apprehension methods most likely to produce convictions. Police officers must be trained to assess when the quality and amount of evidence in a case is sufficient for conviction. Prosecutors should provide feedback to police about how to improve the quality of evidence; they should also pay more attention to cases at an early stage and monitor cases not yet filed by the police.