This June 15, 2010, photo shows the Idaho Correctional Center, operated by Corrections Corporation of America (now CoreCivic). Attorney General Jeff Sessions has signaled his support for the federal government's use of private prisons, rescinding a memo meant to phase out their use. (Charlie Litchfield/AP)

The Justice Department will once again use private prisons to house federal inmates, reversing an Obama-era directive to stop using the facilities, which officials had then deemed less safe and less effective than those run by the government.

In a one-paragraph memo, Attorney General Jeff Sessions rescinded the previous directive to the Bureau of Prisons to either reduce or decline to renew private-prison contracts as they came due.

“The memorandum changed long-standing policy and practice, and impaired the Bureau’s ability to meet the future needs of the federal correctional system,” Sessions wrote. “Therefore, I direct the Bureau to return to its previous approach.”

The directive marks a significant policy shift from the previous administration, although the practical impact might be somewhat muted.

Most inmates are housed in state prisons, rather than federal ones. Even when the Justice Department announced it would no longer use private facilities, the action only affected 13 prisons, housing a little more than 22,000 inmates. The original directive also did not apply to Immigration and Customs Enforcement and U.S. Marshals Service detainees, who are technically in the federal system but not under the purview of the federal Bureau of Prisons.

Private-prison operators already stood to benefit substantially from President Trump’s aggressive measures to detain and deport illegal immigrants.

[The Justice Department closed this troubled private prison. Immigration authorities are reopening it.]

As of Thursday afternoon, the Bureau of Prisons had 12 privately run facilities, holding 21,366 inmates. They are run by three private-prison operators: Management and Training Corporation, the GEO Group and CoreCivic, which used to be known as Corrections Corporation of America.

Private prisons have faced significant criticism in recent years from civil liberties advocates and others. Sally Yates, who served as deputy attorney general in the Obama administration, did not mince words in August when she ordered the Department of Justice — of which the Bureau of Prisons is a part — to end the use of private prisons entirely by phasing them out over time.

“They simply do not provide the same level of correctional services, programs, and resources; they do not save substantially on costs; and as noted in a recent report by the Department’s Office of Inspector General, they do not maintain the same level of safety and security,” Yates wrote.

The inspector general’s report concluded, among other things, that privately operated facilities incurred more safety and security incidents than those run by the federal Bureau of Prisons. The private facilities, for example, had higher rates of assaults — both by inmates on other inmates and by inmates on staff — and had eight times as many contraband cellphones confiscated each year on average, according to the report.

Private-prison operators vigorously disputed that report’s conclusions, and they hailed Thursday’s memo from Sessions as vindication.

[Private-prison industry fights Justice Department directive to end the use of contract facilities]

Jonathan Burns, a CoreCivic spokesman, said the announcement “validates our position that the department’s previous direction was not reflective of the high quality services we have provided to the federal government for decades.” Pablo Paez, a spokesman for the GEO Group, said the company believed the Justice Department’s earlier decision was “based on a misrepresentation,” and it welcomed the reinstatement of “long-standing practice and policy at the Federal level.”

Issa Arnita, a spokesman for Management and Training Corp., said the new directive empowers the Bureau of Prisons “to manage its facilities in a way that provides the greatest value to taxpayers and the inmates in their care.”

The private-prison industry is a formidable one, generating billions of dollars of revenue each year and giving significant amounts to politicians. The GEO Group and CoreCivic, for example, donated $250,000 to support Trump’s inaugural festivities, spokesmen for the companies said. Management and Training Corp. did not, a spokesman said. Separately, the GEO Group, gave $275,00 to the pro-Trump super PAC Rebuilding America Now, according to FEC filings. One $100,000 donation came a day after the Justice Department announced it would no longer use the facilities.

The Justice Department had believed dwindling prison populations would make it possible for the Bureau of Prisons to end its use of contract facilities, and a Justice Department spokesman said in October that still appeared to be the case. Other agencies, though, did not see it that way, even during the Obama administration.

Immigration and Customs Enforcement, for example, inked a contract in October to use a New Mexico facility that the Justice Department had moved Bureau of Prisons inmates out of. The facility has a history of questionable deaths and substandard medical care.

A government panel recommended in December that the Department of Homeland Security continue with its use of private immigrant-detention facilities — saying they were the only realistic way to handle the volatile flows at the border. But the panel’s report was the subject of a contentious debate, and more than two-thirds of a broader government group objected to its conclusion.

David C. Fathi, director of the American Civil Liberties Union’s National Prison Project, said that putting people into for-profit prisons was “a recipe for abuse and neglect,” and the new Justice Department directive seemed to foreshadow the worrisome possibility that “the United States may be headed for a new federal prison boom.” If Sessions believes the Bureau of Prisons could not meet its needs without using for-profit facilities, he said, “you’ve got to wonder what they’ve got up their sleeve.”

Matea Gold contributed to this report.