The study sought to replicate in other jurisdictions the basic aspects of an earlier study of police operations in the District of Columbia, which found that some officers make adult felony and serious misdemeanor arrests that are systematically more likely to produce conviction than the arrests of other officers. The study also conducted further research, largely through intensive interviews in two sites, into the extent to which officer characteristics and special work-related techniques influence the performance of individual officers, in particular their ability to recover physical evidence and to locate and maintain the cooperation of lay witnesses. In part one of the report, following a brief exposition on the seven replication sites, arrest disposition patterns in each jurisdiction are discussed. Factors affecting arrest convictability over which the police have no control are considered, including the inherent convictability of certain types of crime, as well as the relationship between the victim and the defendant. Factors somewhat more under the control of the police are then considered, namely, lay witnesses, recovery of evidence, elapsed time from offense to arrest, and interactions among time, evidence, and witnesses. Officer-related factors affecting arrest convictability are then examined. Part two describes the analysis of the interview data, and the concluding part contains a discussion of the conclusions that emerge from the study. Tabular data and 19 references are provided. For the study summary, see NCJ 80594, and for part 2, see NCJ 82781.