Prison break: states have found ways to reserve prison space for the most serious offenders without jeopardizing public safety.

• Author: Lawrence, Alison
• Position: CRIMINAL JUSTICE

A decade ago, rising prison populations and costs seemed to be an irreversible trend. Since 2007, however, large-scale, data-driven corrections and sentencing reforms in a growing number of states are demonstrating success.

These bipartisan efforts have prioritized prison space for serious and repeat offenders, improved community supervision for other offenders, and re-invested the savings in services that are effective at reducing recidivism and victimization.

Legislatures have reduced penalties for lower-level drug offenders and increased the availability of mental health and substance abuse treatment. They have also focused on providing services and building the skills of inmates to help them succeed after release.

At least 25 states have used what is commonly called justice reinvestment to develop and adopt reforms. This process involves an analysis of the data on what drives prison populations and costs, enactment of policies that address those factors, investments that support carrying out the changes, and oversight and measurement to ensure the desired results are being achieved.

The results are telling. Half the states have reduced their prison population since 2009. Most recently, five states--Alabama, Idaho, Mississippi, Nebraska and Utah--adopted reforms in 2014 and 2015 that collectively have projected savings or avoided costs of more than $1.7 billion over the next two decades.

This impressive work in states is being emulated at the federal level. Proposed bills in Congress would focus federal corrections resources on the most serious offenders. "There's no shortage of admiration for state efforts on the Hill," says Lindsey Carlson of The Pew Charitable Trusts public safety performance project. "Clearly states have led the way and prompted interest in Congress to follow suit."

In September 2015, NCSL and Pew brought together legislators who have championed state efforts to discuss strategies for successful and sustainable reform. Here's what they had to say.

STATE LEGISLATURES: What was the impetus for sentencing and corrections reform in your state?

South Carolina Senator Gerald Malloy (D): The prison population had increased nearly threefold over 25 years, with continued growth projected. Cost was an issue. In 2009 we decided to develop a strategy that would yield a high-performing system.

Former Georgia Representative Jay Neal (R): Instead of spending $264 million to build two new prisons, in 2011 we looked at developing a framework to protect public safety, make proper use of tax payer dollars, and do so mindful of the moral imperative we have to help individuals be law abiding and productive members of society.

California Senator Loni Hancock (D): Our reform has been mainly court driven. Even with significant increases in prison space since the late 1980s, facilities had become so overcrowded that the U.S. Supreme Court told us in 2011 that we had to reduce our population by at least 30,000. It was clear that the public did not want to keep...