Around 15% of the nearly 200,000 inmates in federal custody are housed in privately operated prisons that have come under fire for allegations of poor treatment of prisoners and less stringent security measures — all at a yearly price tag to taxpayers of $639 million. Today, Deputy Attorney General Sally Yates announced plans to phase out the Justice Department’s use of private facilities over the coming years.

In a memo [PDF] sent today to the Acting Director of the Federal Bureau of Prisons, Yates recounts how federal prison populations grew by almost 800% between 1980 and 2013, and how a decade ago the DOJ turned to private prison operators to house a portion of these prisoners.

“Private prisons served an important role during a difficult period, but time has shown that they compare poorly to our own Bureau facilities,” writes Yates, pointing to a recent report from the DOJ’s Office of the Inspector General. “They simply do not provide the same level of correctional services, programs, and resources; they do not save substantially on costs; and… they do not maintain the same level of safety and security.”

The Inspector General’s report looked at data from 14 contract prisons and found that contract prisons had more incidents of lockdowns, discipline, contraband, assaults (on prisoners and staff), and grievances per capita than the Bureau institutions. According to this data, prisoners at contract prisons were eight times more likely to be found with contraband cellphones.

Since 2013, the federal prison population has declined from a high of 220,000 inmates to the current level of around 195,000.

“This decline in the prison population means that we can better allocate our resources to ensure that inmates are in the safest facilities and receiving the best rehabilitative services,” explains Yates in a statement, “services that increase their chances of becoming contributing members of their communities when they return from prison.”

The timeline on the phase-out is a bit vague, as it involves the DOJ not re-upping its contracts with private prison providers as they come up. Yates says the department has already allowed one contract to lapse, which will put around 1,200 prisoners back into prisons operated by the government. And today, Yates says the DOJ has amended a separate contract to reduce the number of prisoners in on private facility from 10,800 to a maximum of 3,600.

While no specific end date was given for the phase-out, Yates’ memo says the goal is to cut the number of prisoners in private facilities by more than half by May 2017.

The Bureau of Prisons accounts for a full quarter of the DOJ’s annual budget, according to Yates.

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