The 1945 cohort contained 9,845 subjects (7,043 whites and 2,902 nonwhites); 3,475 delinquents (2,017 whites and 1,458 nonwhites); and a total of 10,214 offenses (4,458 by whites and 5,756 by nonwhites). The 1958 cohort consisted of 28,338 subjects (6,587 white males and 7,224 nonwhite males; 6,943 white females and 7,584 nonwhite females); 6,545 delinquents (1,523 white males and 2,984 nonwhite males; 644 white females and 1,394 nonwhite females); and a total of 20,089 offenses (4,306 by white males and 11,713 by nonwhite males; 1,196 by white females and 2,874 by nonwhite females). Data indicate that boys born in 1958 and who reached 18 in 1976 were a more violent cohort than urban males born in 1945 and who turned 18 in 1963. The former enter delinquency in about the same proportion (32.6 percent) as the latter (34.9 percent), but the more recent group has engaged in more injurious behaviors. They are more violently recidivistic and commit more Index offenses before reaching 18 years-old. They start their injury offenses earlier and continue longer. The data indicate that the chronic offender is notable both in terms of his/her small proportion of all delinquents and in his/her overwhelming share of delinquencies. The findings suggest that a criminal justice policy that permits an 18-year old to be considered a first-offender adult while ignoring juvenile offenses does not properly deal with the danger to society posed by a person with a serious juvenile record. Tabular data are provided.