AN OUTSTANDING CHARACTERISTIC OF THE JUVENILE JUSTICE SYSTEM IN MARICOPA COUNTY IS ITS SIZE AND COMPLEXITY. MORE THAN 20 POLICE AGENCIES REFER ALLEGED YOUTHFUL OFFENDERS AGED 8 THROUGH 17 TO THE LARGEST JUVENILE COURT IN ARIZONA, WITH THE RESULT THAT THE JUVENILE COURT IS OVEREXTENDED. AN ANALYSIS OF CITY ARREST DATA FOR THE FIVE LARGEST CITIES IN THE COUNTY FOCUSED ON THREE INDICATORS: JUVENILE ARREST TRENDS FROM 1970 TO 1975, PERCENTAGE OF TOTAL ARREST COMPRISED BY JUVENILES, AND ARREST RATES PER 100 JUVENILES AGED 8-17. THE ANALYSIS SHOWED THAT GLENDALE HAD THE HIGHEST PERCENTAGE OF JUVENILE ARRESTS FOLLOWED BY SCOTTSDALE, MESA, TEMPE, AND PHOENIX. THE REPORT NOTES THAT THE COUNTY HAS MANY PROBLEMS RELATED TO ITS POPULATION GROWTH, SINCE IT IS THE FOURTH FASTEST-GROWING AREA IN THE NATION. FOR EACH PROBLEM AREA, THE REPORT DELINEATES DATA, PRESENTS GOALS, AND LISTS SPECIFIC OBJECTIVES TO IMPLEMENT THESE GOALS. THE JJDP PLAN FOR MARICOPA COUNTY CONTAINS 39 OBJECTIVES, 14 OF WHICH WILL BE ADDRESSED WHOLLY OR PARTLY BY JJDP FUNDS. ABOUT ONE-THIRD OF THE 1978 FUNDS WILL BE SPENT FOR PREVENTION, WITH EMPHASIS PLACED ON TWO STUDIES THAT RESEARCH ENVIRONMENTAL FACTORS AFFECTING FAMILIES AND A COMMUNITY NEEDS ASSESSMENT FOR YOUTH DEVELOPMENT. TABLES ARE SUPPLIED. A MAP, A CHART SHOWING GOALS AND OBJECTIVES, AND A REPORT ON CAUSES OF DELINQUENCY AND STRATEGIES FOR CHANGE ARE APPENDED.