Research into career patterns of serious juvenile offenders is reviewed, and the influence of family factors, sociodemographic characteristics, and alcohol and drug use on serious delinquency is examined. The ineffectiveness of the juvenile justice system in dealing with serious and chronic juvenile delinquents is noted. The SHO/DI model and its components are described. The model is based on a systems and organizational development approach that emphasizes the importance of data collection and analysis and interagency cooperation in identifying and managing the target population. The role of police, juvenile courts, schools, probation and parole services, prosecutors, and other juvenile-related agencies in the program is delineated. The development of strategies for identifying SHO/DI targets, profiling, and crime analysis is discussed. Initial phases of program implementations at demonstration sites in Florida, California, and Colorado also are described. Bibliography, chapter references, and endnotes. For individual papers, see NCJ 108315-108332.