Multiple Poisson and logistic regression analyses examined the independent contributions made by symptom and behavior counts, diagnosed conduct disorder, and social and family factors to the prediction of recorded criminality between ages 17 and 21 years and for age 22 years and older. Previous convictions were highly predictive of every offending outcome examined except convictions for violent offenses. Among males, symptoms of hyperactivity were independently predictive of convictions at age 17-21, multiple offending as indicated by 5 or more separate convictions, and having received a custodial sentence. A childhood diagnosis of conduct disorder made little additional contribution to the prediction of later offending over and above the effects of previous convictions. Findings indicated that symptoms of hyperactivity increased the risk of later convictions among boys with behavioral or emotional disturbances in ways not mediated by previous convictions or other measures of childhood conduct problems. Tables, figures, footnotes, and 41 references (Author abstract modified)