THE DATA COLLECTED FOR THIS STUDY ARE BASED ON DETAILED RECORDS OF POLICE CONTACTS WITH TWO COHORTS OF PEOPLE, ONE BORN IN 1942 (N=1,352) AND THE SECOND BORN IN 1949 (N=2,099) IN RACINE, WIS., (POPULATION 100,000). IN ADDITION, 333 PERSONS FROM THE 1942 COHORT AND 566 PERSONS FROM THE 1949 COHORT WERE INTERVIEWED AND THEIR RESPONSES INTEGRATED WITH OFFICIAL POLICE CONTACT RECORDS AND COURT RECORDS, IN ORDER TO BETTER EXPLAIN CONTINUITIES IN DELINQUENT AND CRIMINAL CAREERS. IT WAS CONCLUDED THAT AGE AT FIRST POLICE CONTACT IS THE BEST PREDICTOR OF JUVENILE DELINQUENCY SERIOUSNESS SCORES; THESE SCORES ARE IN TURN THE BEST PREDICTOR OF INTERMEDIATE SERIOUSNESS SCORES; AND INTERMEDIATE SCORES THE BEST PREDICTOR OF ADULT SERIOUSNESS SCORES. BEING MALE, HAVING FRIENDS IN TROUBLE WITH THE LAW, GOING TO WORK AT AN EARLY AGE, AND PERCEIVING HEAVY POLICE PATROL ACTIVITY IN ONE'S NEIGHBORHOOD WERE FACTORS LINKED WITH AN EARLY AGE OF FIRST POLICE CONTACT FOR THE 1942 COHORT; WHILE THE FIRST TWO OF THE AFOREMENTIONED FACTORS, HIGHER LEVELS OF AUTOMOBILE USE, LOWER SOCIOECONOMIC STATUS OF SOCIAL AREA OF RESIDENCE, AND A MORE NEGATIVE ATTITUDE TOWARD THE POLICE WERE FACTORS RELATED TO EARLY AGE OF POLICE CONTACT FOR THE 1949 COHORT. WHILE POLICE CONTACTS FOR ALLEGED DELINQUENT AND CRIMINAL BEHAVIOR ARE WIDE-SPREAD, A CONCENTRATION OF CONTACTS IS FOUND IN THE INNER CITY. ALTHOUGH THE PREDICTIVE MODEL DEVELOPED SHOWS THAT THE EARLY ONSET OF A JUVENILE CAREER (AS DEFINED BY POLICE CONTACT) WILL RESULT IN THE GENERATION OF MORE POLICE CONTACTS AND MORE SERIOUS CONTACTS THAN WOULD BE TRUE OF LATER POLICE CONTACT, IT REMAINS TO BE EXPLAINED WHETHER EARLY POLICE CONTACT RESULTS FROM: (1) AN EARLY ONSET OF DELINQUENT BEHAVIOR, (2) CHANCE, OR (3) EARLY IDENTIFICATION AND LABELING BY THE POLICE, SUCH THAT THE PERSON IS OBSERVED MORE CAREFULLY. DATA DERIVED FROM THE STUDY ARE PROVIDED IN TABULAR FORM. (RCB)