THOUGH THE DATA REFLECTS A HIGH CONCENTRATION (65 PERCENT) OF CRIMINAL/DELINQUENT ACTIVITY BEING COMMITTED BY THE UNDER 26 AGE GROUP, IT DOES NOT NECESSARILY FOLLOW THAT YOUNG PEOPLE ARE MORE CRIMINAL THAN ADULTS. THIS STUDY WAS BASED UPON A SAMPLE OF 12,870 DEFENDANTS CHARGED WITH NEW OFFENSES DURING THE COMBINED 4-WEEK PERIOD. DAILY TABULATIONS MADE DURING THIS PERIOD RECORDED SPECIFIC OFFENSES BY AGE AND SEX OF DEFENDANT. THESE OFFENSES WERE GROUPED ACCORDING TO CRIMES AGAINST PERSON, CRIMES AGAINST PROPERTY, NONASSAULTIVE SEX OFFENSES, MAJOR MOTOR VEHICLE OFFENSES, PUBLIC ORDER CHARGES (SUCH AS SETTING UP A LOTTERY OR NONSUPPORT), AND CONTROLLED SUBSTANCE VIOLATIONS. EACH PERSON WAS COUNTED ONLY ONCE REGARDLESS OF THE NUMBER OF CHARGES AND ONLY THE MOST SERIOUS CHARGE WAS INCLUDED. THE YOUNG ADULT POPULATION (17-25 YEARS OF AGE) RANKED FIRST IN FREQUENCY OF ARRAIGNMENTS; 3 TIMES MORE THAN JUVENILES AND NEARLY 1.5 TIMES MORE THAN OLDER ADULTS. ALSO, YOUNG ADULTS REPRESENTED THE HIGHEST PERCENT OF DEFENDANTS ACROSS ALL SIX CRIME CATEGORIES. THIS MAY BE DUE TO THE FACT THAT OLDER ADULTS ARE MORE ABLE TO ENGAGE IN WHITE COLLAR CRIMES WHICH OFTEN GO UNDETECTED. THE STATISTICS SHOW THAT PROPERTY CRIMES AND CONTROLLED SUBSTANCE VIOLATIONS DECREASE IN FREQUENCY AMONG THE OLDER ADULTS. DEMOGRAPHIC SHIFTS IN POPULATION, THEREFORE, MAY HAVE A PROFOUND EFFECT ON FUTURE ARREST RATES. ECONOMICALLY RELATED CRIMES SUCH AS PROPERTY, SEX, AND SOME MOTOR VEHICLE OFFENSES ACCOUNTED FOR ABOUT HALF OF ALL 1978 CRIMES IN THIS STUDY. FUTURE ECONOMIC DOWNTURNS MAY RESULT IN GREATER INCREASES IN SUCH CRIMES. STATISTICAL TABLES ARE INCLUDED, BUT NO REFERENCES ARE PROVIDED. (KCP)