The participants were all less than 18 years of age at the time of their imprisonment for their current offense and had all been tried and sentenced as adults and placed in adult correctional facilities. Based on their current criminal offense, participants were categorized as either violent (43 offenders) or nonviolent (41 offenders). They took part in psychological evaluations using several instruments and also completed semistructured interviews lasting from 2.5 to 4.5 hours. Results indicated that violent and nonviolent serious juvenile offenders may differ with respect to their prior criminal experiences, their familial and interpersonal relationships, their socioeconomic backgrounds, their developmental etiology, and their psychological makeup. Results indicated the need for improved early identification and intensive rehabilitation of juvenile offenders by the criminal justice system and professional counselors. In addition, improved efforts are needed to prevent juvenile delinquency through developing and establishing positive and healthy family and interpersonal relationships. Tables and 27 references