Samples were stratified by ethnic group (black and white in Baltimore; and black, white, and Hispanic in New York). The amount and type of crime were compared across groups, cities, and drug addiction status (actively addicted or not actively addicted) using different measures based on the concept of crime days per year at risk. Consistent with previous findings, drug addicts engaged in a great deal of criminal activity, especially during periods of active addiction. Differences in the amount and type of crime committed were found among ethnic groups and, to a lesser extent, between cities. For the Baltimore sample, a comparison of findings with those derived from a 1973-1978 data base suggested the amount of crime committed by drug addicts increased in several specific categories and overall. Minor differences in data, however, rendered this finding suggestive rather than conclusive. 8 references and 2 tables