Property crimes are committed primarily for self-gratification/pleasure and utilitarian need. Violent crimes are committed primarily for retaliation/revenge. Drug offenses are committed primarily because of social pressure, with self-gratification/pleasure also an important reason. With isolated exceptions, these findings hold for less and more serious crimes and across a variety of subgroups. The findings are important because they shed light on the origins of specific delinquent acts or events. In particular, the results provide information on the relative utility of three theories of delinquent events: rational-choice theory and modified versions of strain and subcultural-deviance theory. 5 tables, 2 notes, 46 references. (Author abstract)