1. Introduction; 2. The Offenders Index (OI) and the Risk/Rate Model; 3. Application to the Cambridge Study in Delinquent Development (CSDD); 4. Childhood Prediction of Risk/Rate categories in the CSDD; 5. Application to the Pittsburgh Youth Study (PYS); 6. Childhood Prediction of Risk/Rate Categories in the PYS; 7. Final Conclusions.