This study was occasioned by a change in New York City's policing strategy, beginning in the mid-1990's, that emphasized the use of police power to enforce laws that pertained to conduct viewed as harming the community's quality of life. Many of the resulting arrests were for behaviors statutorily defined in the New York State Penal Law or in city ordinances as misdemeanors or lesser-severity offenses. The study found there were more than twice as many arrests for nonfelony offenses in 1998 than in 1989, and there were differences in the composition of the cases. There were changes in the charge-severity distribution of prosecuted summary-arrests for nonfelonious offenses. In addition to doubling arrest volume, the crime characteristics of prosecuted nonfelony arrests were different between the two periods, with varying representation of crime types and different mixtures of charges within some examined crime categories. Changes in enforcement strategies and the resulting arrest patterns produced noticeable differences in defendant characteristics, including criminal record, age, ethnicity, and sex. Further, the court appearance at which cases were completed and the types of dispositions differed in the two time periods. Also, there were differences in the patterns of change between arrest and conviction charge severities when comparing cases in which defendants were convicted. Case outcomes were in turn affected by defendants' criminal record. There were differences between the two time periods in the use of jail sentences for convicted defendants. A jail sentence, including time served and postconviction jail time, was imposed in a greater percentage of the cases in which defendants were convicted in 1989 than in 1998, and the average number of jail days was less in 1998 than in 1989. 50 tables