"Much of America’s serious violent crime is perpetrated by repeat offenders who, in many cases, could have been (but were not) behind bars at the time of their offense."

In the Manhattan Institute, Rafael Mangual reports on the issue of mass decarceration.

The size of America’s prison population is driven by the incarceration of violent felons. These felons are held mostly in state prisons, which account for nearly 90% of inmates nationwide. Most prisoners are serving time for violent or weapons offenses, and the vast majority of them—even those incarcerated for nonviolent drug and property offenses—will go on to re-offend, sometimes by committing serious or violent felonies.

Slashing the prison population to match levels in the Western European democracies would require releasing significant numbers of violent and chronic offenders serving time for crimes that most Americans agree should lead to prison. Reducing or eliminating sentences would diminish the incapacitation benefits of incarceration and, given the extremely high rates of recidivism, would expose society to large numbers of people likely to commit more crimes.

1. Most prisoners are serving short sentences for serious, violent crimes.

60% of state prisoners are serving time for murder, rape, assault, robbery, or burglary—four times the number convicted only of drug offenses.
Despite the portion of prisoners in for serious and violent offenses, less than 15% of state felony convictions result in more than two years served in prison; even 20% of those imprisoned for murder, and nearly 60% of those imprisoned for rape or sexual assault, serve less than five years of their sentences.

2. Most prisoners will re-offend post-release.

83% of released state prisoners are arrested for a new offense at least once after their initial release.
More than one-third of those convicted of violent felonies in large urban counties had an active criminal-justice status—that is, either on probation, parole, or out pending the disposition of a prior case—when they committed their offense.

…Much of America’s serious violent crime is perpetrated by repeat offenders who, in many cases, could have been (but were not) behind bars at the time of their offense. Large-scale decarceration promises to make the problem worse.

Read more here.