LOUISVILLE, Ky. - An independent study has found that inmates released early under a new state law are less likely to re-offend.

The Courier-Journal reports the study by the nonprofit Pew Charitable Trusts is the first to quantitatively measure how successful the law has been.

The measure took effect in 2012. It is aimed at saving $420 million over 10 years by decreasing the number of prisoners in part by releasing some early under supervision.

The Pew study tracked some of the first prisoners released and found that they were 30 percent less likely to commit new crimes compared to inmates released in previous years with no supervision.

"It's very exciting to see a state use data and research to drive policy, get beyond partisan posturing, and have such great initial results," said Adam Gelb, director of Pew's Public Safety Performance Project.

Rep. John Tilley, D-Hopkinsville, who led the task force that composed the legislation, said it isn't easy to measure the overall success of the reforms. He said municipalities have saved about $40 million.

Louisville Metro Department of Corrections Director Mark Bolton said the jail has the lowest number of inmates in 10 years.