The study made lower-bound estimates of how many individuals from particular population groups that resided in the District of Columbia were involved in drug-related criminal activities. It also examined trends in drug and nondrug charges in the District of Columbia and disentangled the age, cohort, and period effects in the variation in participation in drug offenses across multiple birth cohorts in the city. The study estimated that up to 30 percent of the young, black male population of the city were charged with drug distribution during this time. Charge rates for drug distribution activities appeared to peak around age 24, decreasing slowly thereafter. Large and nonlinear period effects were observed for all drug-related charge rates, and increasing linear period effects were found for nondrug misdemeanors. Cohort effects in drug-related charge rates were also observed. Levels of participation in drug distribution charge rates were lower for older cohorts, and the cohort share with a drug-possession charge declined for younger cohorts. When age and period effects were included in the models, however, these cohort effects were muted or disappeared, except in the case of nondrug misdemeanors. 6 tables, 4 figures, and 50 references