Two in five people released from prison in Massachusetts return to the community without the supervision of a probation or parole officer, according to a review of the state’s criminal justice system released by the nonpartisan Council on State Governments Tuesday.

The rate of supervision is one of the lowest in the country, according to analysts with the organization, which has conducted similar assessments in 23 other states.

The findings, which also include a sizable drop in drug arrests and convictions over the last several years, is just the start of a months-long examination of the state’s criminal justice system that could lead to significant policy shifts.

Governor Charlie Baker, Senate President Stanley C. Rosenberg, House Speaker Robert A. DeLeo, and Ralph D. Gants, chief justice of the Massachusetts Supreme Judicial Court, requested the analysis in August, lending substantial political heft to the effort.

“I think it’s very positive that the top leaders on Beacon Hill are all focusing together on real data about the criminal justice system,’’ said state Senator William Brownsberger, a Belmont Democrat who cochairs the Legislature’s Joint Committee on the Judiciary. “I can’t think of a conversation that is more likely to lead to support for real reforms.’’

It’s not clear, though, what sort of changes might emerge from the process. The council’s review is in the early stages, and policy recommendations won’t land until the fall.

But the group did lay out some areas of exploration on Tuesday. Council staff said they will examine how bail decisions are made, whether offenders with substance abuse problems have access to proper services, and how quickly convicts can get released from prison for good behavior.

The review comes amid a national reconsideration of the tough-on-crime policies of the 1980s and 1990s.

Dozens of states have moved to overhaul their criminal justice systems, with support ranging across the political spectrum. Republican presidential hopeful Ted Cruz and presumed Democratic front-runner Hillary Clinton have both called for change.

In Massachusetts, liberal lawmakers were pressing for an overhaul before the Council on State Governments review began. But it’s unclear what the political prospects of some of the marquee proposals might be.

An effort to repeal mandatory minimum sentences for drug convictions, for instance, has run into stiff opposition from prosecutors. And Baker, a Republican, has been cool to a major overhaul, repeatedly pointing out that Massachusetts has one of the lowest incarceration rates in the country.

Steve Allen, a senior policy adviser with the Council on State Governments, emphasized during a State House presentation Tuesday that the Massachusetts system is not in crisis.

“The good news,’’ he said, “is that, in this initial analysis of public records, we’re not finding a house on fire.’’

But without a burning issue to address, council staffers said, the state has an opportunity to get creative.

One area of broad concern for the political players, law enforcement, the judiciary, and advocates for offenders is the parole and probation system.

A Pew Charitable Trusts study released in 2014 found that the number of inmates nationwide who “maxed out’’ — serving their entire sentences behind bars and returning to the street without supervision or support — grew by 119 percent between 1990 and 2012.

The review chalked up the growth, in part, to state policies that require inmates to serve more of their sentences — so-called “truth-in-sentencing’’ laws, for instance.

Only six states — South Carolina, Ohio, Oklahoma, North Carolina, Maine, and Florida — had higher “max-out’’ rates than Massachusetts in 2012, according to the study. Four of those states have since enacted policies to increase post-imprisonment supervision.

Staff with the Council on State Governments said Massachusetts’ high max-out rate, with two in five people released from prison going unsupervised, owes something to recent controversies.

The fatal shooting of a Woburn police officer in 2010 by a career criminal out on parole led to a sharp drop in the use of parole. And the state’s drug lab scandal, which involved chemist Annie Dookhan tampering with evidence, led to the release of inmates who, with their convictions tossed out, did not require supervision.

Marc Pelka, program director with the council, said there is also a lot to be learned about the effectiveness of the state’s probation system, which does not publicly report on the recidivism rate of those who go through the system.

Pelka and his colleagues presented their initial findings at the State House to a working group of elected officials, sheriffs, judges, and others around a collection of tables arranged in a rectangle and covered in white tablecloths and bottled water.

The group, which asked council staff a series of clarifying questions and pressed for additional data, is scheduled to meet six times over the course of the year. In the fall, the officials are expected to settle on a series of policy proposals that the Legislature could take up at the start of 2017.

The Council on State Governments has guided several other states through similar processes, ending with a governor’s signature on substantial legislation.

Brownsberger, the cochairman of the Legislature’s Judiciary Committee, said he hopes the Massachusetts process will find a similar end. But in the meantime, he added, lawmakers may move on a series of more modest reforms.

David Scharfenberg can be reached at david.scharfenberg @globe.com.