In the Oregon Youth Study (OYS) during the interval from Grades 4 through 12, there was significant growth in covert antisocial behavior. Mothers’ ratings collected each year defined intraindividual growth curves for 206 boys living in high-crime areas. The growth curves were grouped into five categories. The category «chronic» covert growth described boys who initiated the growth early and scored above the mean for five or more points in time. The category was associated with both juvenile (49%) and adult recidivism (41%). Those growth curves categorized as at only «moderate risk» showed 16% juvenile and 09% adult recidivism. We hypothesized that the significant correlation between childhood measures of overt antisocial behavior and adult arrest would be mediated by the level of growth in covert antisocial behavior. The findings supported the mediational model.