A 3-year study of over 400 detained juveniles was conducted to determine the benefits of urine tests for identifying youngsters at high risk for future criminal behavior. The study consisted of interviews and urine tests of juveniles as they entered detention centers in Tampa, Florida. Follow-up interviews and drug tests were later performed to determine patterns of drug use, criminality, and behavioral and psychological adjustment. Juveniles' self-reports of drug use were compared to their urine tests. The results of the study concluded that juveniles were likely to accurately report their marijuana use, but they were less likely to accurately report their use of illicit drugs. Also, juveniles who were tested positive for drugs initially were much more likely to be tested positive and re-arrested for more serious offenses by the time the follow-up interviews occurred. Increased drug testing of juveniles and development of drug treatment programs for juvenile offenders is recommended. 17 footnotes. 44 references.