USING RELEVANT DEFINITIONS GATHERED FROM A REVIEW OF THE LITERATURE, STATISTICS, AND EXPERT OPINION CONCERNING JUVENILE DELINQUENTS, THIS REPORT ASSESSES PATTERNS AND TRENDS OF SERIOUS JUVENILE CRIME; SPATIAL DISTRIBUTION, CONTEXTS, AND SETTINGS OF SERIOUS JUVENILE CRIME; AND CHARACTERISTICS OF JUVENILES ARRESTED AND ADJUDICATED FOR SERIOUS OFFENSES. ASSESSMENT OF THESE TOPICS WAS BASED ON AN INFORMAL SURVEY, A REVIEW OF AVAILABLE NATIONAL DATA, A NATIONWIDE SURVEY OF STATE AGENCIES, AND A GENERAL LITERATURE SEARCH ON RELEVANT CHARACTERISTICS. ANOTHER ASSESSMENT CONCERNING THE STATE OF KNOWLEDGE OF THE RELATIONSHIP BETWEEN SUBSTANCE ABUSE AND SERIOUS CRIME AMONG JUVENILES USED ABSTRACTS, REFERENCE LISTS, AND INDEXES OF LITERATURE FROM 1968 THROUGH 1978. ALL BUT 4 OF THE 77 SUBSTANCE ABUSE STUDIES WERE CONCERNED PRIMARILY WITH ADULTS; YET ALL HAD SOME RELEVANCE FOR JUVENILE DRUG ABUSE AND SERIOUS CRIME. STATUTES IN THE UNITED STATES THAT RELATE TO THE SERIOUS JUVENILE OFFENDER, AND ARE REPORTED HERE, WERE DERIVED FROM A STATUTORY ANALYSIS OF FEDERAL GUIDELINES AND JUVENILE LAW IN THE 50 STATES AND THE DISTRICT OF COLUMBIA CONCERNING THE DISPOSITIONAL METHODS CREATED SPECIFICALLY FOR DEALING WITH THE SERIOUS JUVENILE OFFENDER. STATUTORY PROVISIONS REGARDING THE JURISDICTION OF THE JUVENILE COURT AND THE CRIMINAL COURT OVER YOUTHS UNDER THE AGE OF 18 IN ALL 51 STATE JURISDICTIONS ARE ALSO PRESENTED. A TOTAL OF 14 PROGRAMS FOR THE INTERVENTION AND TREATMENT OF SERIOUS JUVENILE OFFENDERS ARE EVALUATED. OTHER TOPICS ASSESSED INCLUDE THE CONFIDENTIALITY OF JUVENILE RECORDS AND THE ECONOMIC IMPLICATIONS OF SERIOUS JUVENILE CRIME. OVERALL, THE ASSESSMENT SHOWS THAT FEDERAL, STATE, AND LOCAL RESOURCES AND POLICIES SHOULD CONCENTRATE ON SEVERE OFFENSES, CHRONIC OFFENDERS, AND THE DEVELOPMENT OF A RATIONAL RESPONSE TO JUVENILE CRIME THROUGH IMPROVED RESEARCH, STATISTICS, LAW, PROCEDURES, AND PROGRAMS. A TABLE ILLUSTRATES THE SELLIN-WOLFGANG SERIOUSNESS SCALE. FOOTNOTES ARE INCLUDED. NAMES OF THE STAFF, ADVISORY COMMITTEE, AND PROGRAM MONITORS FOR THE JUVENILE JUSTICE SYSTEM ASSESSMENT CENTER ARE APPENDED. FOR A FULL REPORT, SEE NCJ 65399 THROUGH 65401.