THE MASSACHUSETTS DEPARTMENT of Correction on Thursday made a surprising announcement: MCI-Cedar Junction in Walpole will stop housing prisoners over the next two years.

The reason the department gave was declining numbers of inmates and increasing costs. Or, in DOC-speak, “a thorough assessment of decreased housing needs and the aging facility’s exorbitant maintenance costs.”

But in many ways, the closure is the result of a broader trend, which is the state’s move in recent years away from a “tough on crime” approach and toward a “smart on crime” one.

Democratic Sen. Jamie Eldridge, who co-chairs the Legislature’s Judiciary Committee, said he was “overjoyed” to hear of plans to close MCI-Cedar Junction. “This is a real watershed moment in the move away from mass incarceration to close a prison,” Eldridge said. “I am hopeful that the next phase is investing the money that’s now spent on Walpole prison into education, into training, and justice reinvestment in communities disproportionately impacted by the war on drugs and the mass incarceration era.”

MCI-Cedar Junction today is operating at 68 percent capacity, housing 525 inmates. It opened in 1955 and needs $30 million in infrastructure repairs to keep operating, according to DOC.

Within the next 60 to 90 days, a reception and diagnostic center, where inmates are held when they enter custody and evaluated to determine their security level, will move from Walpole to Souza-Baranowski Correctional Center. Inmates in a Behavioral Management Unit will be moved to other units in 2024. A disciplinary unit will be closed after that, in line with the state’s commitment to phase out solitary confinement.

“This decision, and the subsequent consolidation of resources across fewer locations, allows us to eliminate redundancies and deepen our investments in programming, staffing, and services,” said DOC Commissioner Carol Mici.

The last state prison to close was the small, medium security Bay State Correctional Center in Norfolk in 2015.

The closure comes as the state is moving forward with implementing the 2018 criminal justice reform bill. The bill is a manifestation of the state’s more modern approach to criminal justice, which aims to keep low-level offenders out of the criminal justice system, and divert as many people as possible to treatment, education, and other programs. Even once someone commits a crime, there has been a growing drive to reserve jail time for only the most serious crimes – and not, for example, for people who cannot afford bail.

Earlier this week, the Legislature’s criminal justice reform caucus, led by Eldridge and Rep. Mary Keefe, wrote to Gov. Charlie Baker and correction officials urging them to close women’s and men’s correctional facilities because of the Commonwealth’s declining prison population.

“Many studies have highlighted how savings from prison closures could instead be diverted to invest in training, prevention, education, and re-entry services, which are all proven to decrease overall incarceration and recidivism rates,” the lawmakers wrote.

The letter said the state prison population has declined enormously over the last decade. In 2010, there were 11,361 offenders in state prison; in December 2021, the Department of Correction reported 6,255 incarcerated inmates. Part of the decline is because Massachusetts made an effort to keep people out of jails during the COVID pandemic. State officials cited a Vera Institute for Justice report, which found that Massachusetts’s incarceration rate was the lowest in the country after declining by 2,000 during the pandemic.

The problem, however, as laid out in a recent report by a special commission formed to look at correctional spending, is that even though the inmate population has declined over the past decade, correction spending has not. A major reason is staffing levels have not declined alongside inmate counts. The report cites several reasons for this: an increase in programming, older facilities that require more staff, a more violent population that requires more supervision, and the fact that population declines do not necessarily translate into housing unit closures.

Commission co-chair Sen. William Brownsberger said when the report was released that the only way to lower costs is by closing housing units.

Lizz Matos, executive director of Prisoners’ Legal Services, said her agency will be watching how the closure is implemented. She wants to make sure people admitted to the new admissions center at Souza Baranowski do not spend months under maximum security conditions if they belong in a lower-security facility. She wants to ensure the closure does not result in overcrowding elsewhere.

It’s unclear whether another prison closure could be coming. Then-Public Safety Secretary Thomas Turco said in 2020 that the state had plans to close the women’s prison at MCI-Framingham. That prison was initially built in 1877 and portions of it have already closed due to problems with aging infrastructure. But the effort faced opposition to building a replacement women’s prison, and the state now appears to be waiting on a consultant’s report about its prison needs before moving forward.