A federal judge overseeing New York City’s jails took Rikers Island out of the city’s control on Tuesday, ordering that an outside official be appointed to make major decisions regarding the troubled and violent jail complex.

The judge, Laura Taylor Swain, said in a 77-page ruling that the official would report directly to her and would not be a city employee, turning aside Mayor Eric Adams’s efforts to maintain control of the lockups. The official, called a remediation manager, would work with the New York City correction commissioner, but be “empowered to take all actions necessary” to turn around the city’s jails, she wrote.

“While the necessary changes will take some time, the court expects to see continual progress toward these goals,” Judge Swain wrote.

The order comes nearly a decade after the city’s jails, which include the Rikers Island complex, fell under federal oversight in the settlement of a class-action lawsuit. The agreement focused on curbing the use of force and violence toward both detainees and correction officers. A court-appointed monitor issued regular reports on the persistent mayhem.

New York City has held onto its control of Rikers with white knuckles — struggling to show progress and reaching the brink of losing oversight of the jails as critics of the system have called for a receiver. Conditions have not improved, according to lawyers for the plaintiffs and the federal monitor.

The city’s jail population has grown to more than 7,000 from a low of about 4,000 in 2020. And in the first three months of this year, five people died at Rikers or shortly after being released from city custody, equaling the number of detainees who died in all of 2024.

In a statement, lawyers from the Legal Aid Society and Emery Celli Brinckerhoff Abady Ward & Maazel, which represent detainees, said they commended the court’s “historic decision.”

“For years, the New York City Department of Correction has failed to follow federal court orders to enact meaningful reforms, allowing violence, disorder and systemic dysfunction to persist,” said Mary Lynne Werlwas and Debra Greenberger. “This appointment marks a critical turning point.”

The remediation manager will be a receiver in all but name. The official will be granted “broad powers” as plaintiffs had asked, Judge Swain wrote, but will also develop a plan for improvement in concert with the correction commissioner.

Such arrangements are the last resort for a troubled jail or prison. Since 1974, federal courts have put only nine jail systems in receivership, not counting Tuesday’s Rikers order.

The ruling was another blow for Mr. Adams, who is fighting for his political life after the Trump administration dropped corruption charges against him so that he could assist with its deportation efforts. Many of his confidants have also faced investigations, he is on his fourth police commissioner and his approval ratings have hit historic lows.

Now, the mayor, a former police captain, has lost most control of an institution that employs about 5,000 people represented by the Correction Officers’ Benevolent Association, a union that has been a bastion of political support.

On Tuesday, even as prisoners rights organizations and some of Mr. Adams’s campaign opponents celebrated, the mayor disputed whether Judge Swain’s order constituted a receivership and painted it as a benefit.

“The problems at Rikers are decades in the making,” he said. “We finally got stability.”

In a statement, Benny Boscio, president of the correction officers’ union, said that Judge Swain’s order had preserved the right to representation and collective bargaining, and he made clear that the guards must be reckoned with.

“The city’s jails cannot operate without us,” he said. “And no matter what the new management of our jails looks like, the path toward a safer jail system begins with supporting the essential men and women who help run the jails every day.”

New York City has spent more than $500,000 per inmate annually in recent years, according to city data, well beyond what other large cities have spent, and yet detainees still sometimes go without food or proper medical care.

A New York Times investigation in 2021 found that guards are often stationed in inefficient ways that fail to protect detainees. And although the jail system has consistently been the most well-staffed in the United States — there is roughly one uniformed officer for each inmate at Rikers, according to city data — an unlimited sick leave policy and other uses of leave have meant that there are too few guards present to keep inmates safe.

The class-action lawsuit that led to the takeover, known as Nunez v. City of New York, was settled in June 2015 and required that the jails be overseen by a court-appointed monitor who would issue regular reports on conditions there but would wield no direct power to effect change.

Through those reports, Judge Swain was given an extensive history of the cyclical nature of the jail system’s problems. Through the administration of two mayors and several correction commissioners, the jails continued to devolve, according to prisoners’ rights advocates and the monitor’s reports. In November, the judge found the city in contempt for failing to stem violence and excessive force at the facility, which is currently run by Correction Commissioner Lynelle Maginley-Liddie.

Over the years, the city has argued that the Department of Correction has made progress, even as Judge Swain issued remedial orders and the monitor and prisoners’ advocates pointed to backsliding.

In 2023, Damian Williams, then Manhattan’s top prosecutor, joined calls for the appointment of an outside authority to take control of Rikers, saying that the city had been “unable or unwilling” to make reforms under two mayors and four correction commissioners.

On Tuesday, Jay Clayton, whom President Trump appointed last month as interim U.S. attorney, said Judge Swain’s decision was a “welcomed and much needed milestone.”

In a 65-page opinion last year, Judge Swain said that the city and the Department of Correction had violated the constitutional rights of prisoners and staff members by exposing them to danger, and had intentionally ignored her orders for years. Officials had fallen into an “unfortunate cycle” in which initiatives were abandoned and then restarted under new administrations, she wrote.

An inability to operate independently of politics is what has kept Rikers from turning around, said Elizabeth Glazer, the founder of Vital City and a former criminal justice adviser under Mayor Bill de Blasio.

“Every new administration, there’s a reset,” she said. “Every new crisis, there’s a reset.”

Last year, Judge Swain ordered city leaders to meet with lawyers for prisoners to create a plan for an “outside person,” known as a receiver, who could run the system.

The parties met in recent months to try to reach an agreement, in deliberations overseen by the federal monitor, Steve J. Martin. He told the court that the parties and his team had been “actively engaged” in discussions.

In the end, the sides submitted dueling proposals.

The Legal Aid Society and a private law firm representing incarcerated people argued that the court should strip the city of control and install a receiver who would answer only to the court. The receiver should be given broad power to make changes, they proposed, including with regard to staffing and union contracts that govern it.

The receiver, they said, could “review, investigate and take disciplinary or other corrective or remedial actions with respect to violations of D.O.C. policies, procedures and protocols” related to the court order.

In its plan, the city offered to give Ms. Maginley-Liddie dual roles by adding the title of “compliance director” to her responsibilities. The city proposed that she answer to the court on issues related to the consent decree, such as safety and staffing shortages, while answering to the mayor on everything else.

However, the city has had a “a multitude of opportunities” to improve its management of the jails and has “proven unable or unwilling to take advantage of those opportunities,” said Hernandez D. Stroud, a senior fellow at the Brennan Center for Justice at the New York University School of Law.

“Judge Swain was left no other choice,” he said.

Emma G. Fitzsimmons contributed reporting.