NEW YORK — 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.

“The parole system was a miserable failure,” Judd said.