Since 1974 over 90 percent of all state prisoners have been violent offenders or recidivists. Over 80 percent of imprisoned state and federal drug offenders are drug traffickers with multiple-offense histories. The average quantity of drugs involved in federal cocaine trafficking cases is 183 pounds. In the year prior to their imprisonment, half or more of all prisoners commit at least a dozen serious crimes, excluding all drug crimes. Even if measured only in terms of enhanced public safety, the cost to society of letting most violent or repeat prisoners out early is at least twice as much as keeping them in prison for all or most of their terms.
Most violent prisoners serve less than half their time in prison before being released.
On average, murderers released from state prisons in 1992 served only 5.9 years. Despite the enactment of mandatory minimum laws, between 1985 and 1992 the average maximum sentences of prisoners declined about 15 percent from 78 months to 67 months. The juvenile justice system operates as the first revolving door. In 1991 about 51,000 male juveniles were in custody, a third of them for violent offenses. In 1992 alone, there were over 110,000 juvenile arrests for violent crimes and over 1.6 million juvenile arrests for other crimes.