Major findings indicate that chronic offenders were disproportionately male, arrested for the first time by the age of 13, and incarcerated in juvenile training schools. Of the juvenile chronic offenders, 75 percent became adult offenders. The 293 juvenile chronic offenders with an adult arrest were responsible for over half the adult arrests. In addition, 60 of the chronic juvenile offenders (8 percent of the adult offenders) were repeat violent offenders as adults and accounted for a third of all adult arrests for index violence. Most juvenile chronic offenders (54 percent) had been incarcerated, and 63.5 percent with at least one adult arrest went to prison. Of adult chronic offenders, 70 percent went to prison at least once; and had there been no chronic offenders among the cohort, the number of arrests would have been reduced by 50 percent. Thus, it appears that most violent juveniles make the transition to adult criminality; there is a continuity between juvenile and adult criminal careers; relatively few chronic offenders are responsible for a disproportionate number of crimes. Frequency of arrest declined with age; and incarceration did not diminish the crime rate, while it may have increased the subsequent arrest rate.