In the Oregon Youth Study, at-risk boys were interviewed annually from ages 9 to 10 years old to ages 23 to 24 years old. The study explored two key questions: how many and which distinctive offending trajectory groups were empirically identifiable in a sample of young men over time, and were the identified offending trajectory groups associated with specific childhood factors and adolescent covariates? A sample of boys was selected from schools in the higher crime areas of a medium-sized metropolitan region in Oregon. Of the eligible families, 206 agreed to participate. The variables measured were delinquent behavior, parents' police arrests, harsh and inconsistent parental discipline, association with deviant peers, and sociodemographics. The first stage of the data analysis used LGMM (latent growth mixture modeling) to identify distinct developmental trajectories of delinquent behavior from early adolescence (12 to 13 years old) to young adulthood (ages 23-24). The second stage predicted offender trajectory class membership by childhood and adolescent characteristics. Six trajectory classes were identified: chronic high-level, chronic low-level, decreasing high-level, decreasing low-level, rare, and nonoffenders. Multinomial logistic regressions found that nonoffenders, rare offenders, and chronic high-level offenders were distinguished by individual, family, and peer factors measured in childhood and adolescence. Only adolescent covariates (deviant peers, various problem behaviors) distinguished among trajectories of adolescents who engaged in significant amounts of offending behavior. This study adds to the increasing empirical evidence that calls for more differentiated theoretical models of offending trajectories; however, additional research is needed before firm conclusions can be drawn about the optimal number of offending trajectories. 6 tables, 6 notes, and 64 references