Information was obtained through a literature search, site visitation, structured interviews, and telephone surveys. The primary source of information was the operational system of police, court, and correctional agencies. Issues covered by the information are the nature of the problem (definition of the serious juvenile offender and the rehabilitation enigma), serious juvenile offender characteristics, local procedures for the serious juvenile offender, State programs for the institutionalized serious juvenile offender, and major system issues related to the serious juvenile offender. Findings indicate that efforts to address the increased violence and criminality of the relatively small number of serious juvenile offenders are hampered by competing policies: the policy of more severe penalties for such offenders and the movement to deinstitutionalize juvenile offenders. Regarding the local handling of the serious juvenile offender, police agencies are mounting special efforts to deal with the 'hardcore' juvenile. There is significant agreement between police and the courts about the need to retain the traditional focus on rehabilitation for juveniles. There is increased pressure, however, for the juvenile court to become more like the adult court. There is an apparent consensus that services for the serious juvenile offender must reflect a continuum of treatment from disposition through release from parole, based on individualized assessment that includes the juvenile's participation. 8 figures, 5 tables, 185 footnotes.