NEW YORK (AP) — Increasing numbers of prison inmates nationwide are serving their full sentences and then going free without any supervision by parole or probation officers, according to a new report which says the trend is worrisome.

"These inmates do not have any legal conditions imposed on them ... and do not receive the assistance that can help them lead crime-free lives," says the report, released Wednesday by the Pew Charitable Trusts.

It suggests that even short-term supervision would be useful, because offenders are at greatest risk of committing new crimes in the months immediately after release.

According to Pew's analysis of Department of Justice figures, the number of inmates who maxed out their sentences in prison grew 119 percent between 1990 and 2012, from fewer than 50,000 to more than 100,000. These unsupervised inmates represented 22 percent of all prisoners released in 2012, the report said.

It documented a wide variance among the states.

More than 40 percent of released inmates left without supervision in 2012 in Florida, Maine, Massachusetts, New Jersey, North Carolina, Ohio, Oklahoma, South Carolina, and Utah, according to the report. By contrast, fewer than 8 percent of inmates were released without supervision in Arkansas, California, Michigan, Oregon, New Hampshire, and Wisconsin.

Pew attributed the overall increase to policy changes that resulted in offenders serving higher proportions of their sentences behind bars. These included so-called "truth-in-sentencing" laws and, in some states, the outright elimination of parole.

In Florida — with a highest-in-the-nation 64 percent of released inmates leaving prison unsupervised — parole was abolished in 1983 and the Legislature passed a law in 1995 requiring prisoners to serve at least 85 percent of their sentence. That essentially eliminated the parole system for crimes committed after that time, and Pew said 21,000 inmates left Florida prisons in 2012 without supervision.

Polk County Sheriff Grady Judd, who is president of the Florida Sheriffs Association, credits the policies for Florida having its lowest crime rate in 43 years.

"I think it's a great system. When we had the parole system, they only served about a third of their sentence and they were back out on the street committing crime on parole when in fact they should have been locked up. It infuriated the community and it infuriated law enforcement."

"The parole system was a miserable failure," Judd said.

However, Adam Gelb, director of the Pew Charitable Trust's public safety performance project, said most states seemed interested in moving in the other direction.

"More and more policymakers from both sides of the aisle are recognizing that if you're serious about public safety, you need to make sure inmates are supervised once they leave prison," he said. "You shouldn't have inmates going from the cell to the street without any accountability or support. It's not common sense."

The report contended that for many offenders, shorter prison terms followed by supervision could reduce recidivism and overall corrections costs.

It cited a 2013 Pew study which found that New Jersey inmates released to parole supervision before their sentences expired were 36 percent less likely to return to prison than inmates who maxed out.

Pew said the savings from releasing inmates to supervision before the end of their sentences could be substantial, because the cost of supervision generally is a tenth that of incarceration.

According to Pew, policymakers in at least eight states have recently taken steps to ensure that offenders are supervised after release from prison. In some cases, this entailed mandating a period of post-prison supervision for all released inmates — a step which Pew recommended for all states.

"It is especially important for those convicted of violent, serious, or repeat offenses," the report said.

It said less dangerous ex-offenders could be placed on "inactive supervision" to conserve resources, while retaining a mechanism to monitor their residence and employment.

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Associated Press writer Brendan Farrington in Tallahassee, Florida, contributed to this report.

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