Previously, both rehabilitation and deterrence have been shown to be ineffective as criminal justice policy. The current interest in the idea of incapacitation resulted from the rediscovery of the idea of a chronic offender or career criminal. However, further research has shown both that (1) predictions of criminality are inaccurate and (2) offending declines with age after adolescence. It also shows that prior offending is the best predictor of future offending. For maximum effectiveness in controlling crime, incapacitation would be focused on the age period just prior to the rapid onset and peaking of crime. However, incarcerating 13- and 14-year olds after their first offense would be inappropriate, because almost half of all offenders commit only one offense. Similarly, one-third of second offenders do not commit a third offense by the time they are 18. Thus, selective incapacitation treats many low-rate offenders as though they were high-rate offenders. Furthermore, offenders who have committed enough offenses to justify imprisonment will have passed beyond the peak age of crime. A more promising approach to crime control would be a preventive approach that would rest on the recognition that crime occurs mainly among youth and that it occurs mainly in the absence of restraints. Figure and 8 references.