This study investigated violent offending in adolescence and early adulthood with an aim of building practical knowledge to guide prevention programs and policies. The study examined risk factors that influence violent offending and described how offending and risk levels change over adolescence and into early adulthood. The study used data from Waves I to VII of the NATIONAL YOUTH SURVEY (NYS), conducted by Delbert Elliott between 1977 and 1987. Separate datasets for Waves I to VII were merged to create a single longitudinal dataset, using SAS system software. The NYS includes baseline information on youth and family background and demographic characteristics, as well as longitudinal data on the behaviors and attitudes of youths, and youths' perceptions of parent, neighborhood, and peer group factors.