Criminal offending, we well know, is highly concentrated: in serial offenders, a relative few of whom commit a great many crimes; in criminal groups like street gangs; and in particular neighborhoods and in" hot spots" within those neighborhoods. Crime control policy has responded to these concentrations of criminal offending in a variety of ways. Attempts at selective incapacitation sought to identify and incapacitate the worst serial offenders. Certain state and federal laws allow, and sometimes require, sentencing enhancements on the basis of prior convictions, with three strikes laws the most recent variation on this theme. The Federal Bureau of Investigation (FBI) has long taken its goal as the" dismantling" of criminal organizations. In policing, strategies as old as directed patrol and as new as" broken windows" and customized problem solving strategies have addressed high-crime neighborhoods and the hot spots within them. Prosecutors and probation and parole officers, exercising the discretion their offices allow them, have focused their efforts on high-rate and high-risk individuals, groups, and areas.

These approaches share several common elements. Where they focus on individuals, they generally aspire either to taking the individual off the street, as in the case of police and prosecutors, or to individual rehabilitation, as in the case of probation and parole (which can also, of course, bring enforcement and sanctions to bear). Where they focus on groups, they generally aspire to the wholesale elimination of the group, as in the FBI's long campaign against the Mafia, or to the general suppression of the group's offending, as in the usual police strategy against street gangs.'These approaches overlap other approaches aimed at key individuals in particular gangs, as in strategies aimed