Does releasing inmates early cut crime? One study says maybe

Letting offenders out of jail early may have the counter-intuitive effect of lowering crime.

At least that's what a new report by the Pew Charitable Trusts finds. The study contains some of the first evidence that letting offenders out early from jail and prison — under community supervision — lowers crime.

Adam Gelb, director of the Public Safety Performance Project at Pew, said studies the group conducted in New Jersey and elsewhere found that, overall, offenders who serve a portion of their sentence on supervision were arrested or returned to prison 30 percent less than those who served their entire sentence in custody.

"It just doesn't make sense to take somebody who's been institutionalized, locked up in a prison 24/7, and put them straight back on the street without any supervision or accountability or monitoring or support whatsoever," Gelb said. 

Yet nationwide, the number of offenders serving their full sentences has gone up over the past two decades. Between 1990-2012, the number of inmates released without supervision went up 119 percent. 

That could change, Gelb said, and has already started to. In the past few years, eight states — including California — took steps to make it easier to release offenders early to supervision. 

California's policy — called "split sentencing" — came out of prison realignment, which passed in 2011.

The policy — a response to a U.S. Supreme Court order to cut the state prison population — shifted the job of punishing lower-level felons from the state to the county level. It also gave the counties a tool to use if they choose: permitting these felons to be sentenced partially to time in county jail and partially to community supervision by the local probation department.

Some counties, like Riverside County, have grabbed onto split sentencing, using it in 80 percent of cases involving these realigned felons. In L.A. County, the number is about 5 to 6 percent. 

County leaders in the sheriff's department, probation department and district attorney's office have said they're evaluating split sentences to see if they can be better utilized in Los Angeles. 

Gelb said the incentive to change may eventually be financial.

"It's a win-win opportunity to cut costs and cut crime," Gelb said. "Prison costs about $80 a day nationally, and parole costs about $8 a day."

As more judges, prosecutors and law enforcement agencies see evidence that supervision —when done right — can work, Gelb said, he expects more to turn to the less expensive option.