The gang-linked prison chief taking custody of Trump’s deportees

Osiris Luna has been instrumental to Salvadoran President Nayib Bukele’s crusade to end decades of rampant gang violence, overseeing the imprisonment of more than 80,000 people over the past three years.

Many are held at a vast new prison alongside more than 250 alleged Salvadoran and Venezuelan gang members recently expelled by the U.S. under a Trump administration deal that pays Bukele’s government to incarcerate them.

But earlier in Bukele’s presidency, Luna was sanctioned by the U.S. Treasury Department for allegedly arranging secret negotiations with gang leaders aimed at reducing homicides and securing political backing for Bukele. In exchange, incarcerated gang leaders received mobile phones, access to sex workers and other privileges, U.S. prosecutors said in an indictment against MS-13 gang leaders.

The Bukele administration and Luna have denied the U.S. allegations. Luna didn’t respond to requests for comment. A spokeswoman for Bukele didn’t respond to a request for comment.

“We are grateful for President Bukele’s partnership and for Cecot—one of the most secure facilities in the world," said White House spokeswoman Abigail Jackson, referring to El Salvador’s Terrorism Confinement Center, the mega-prison Luna oversees. “There is no better place for these sick criminals."

The White House has said the U.S. is paying El Salvador $6 million to imprison the alleged gang members. Under the deal, the Trump administration has returned MS-13 gang leaders imprisoned in the U.S. to El Salvador, where constitutional rights and due process have been suspended since 2022. Deporting them to El Salvador would mean they couldn’t testify in U.S. court, shielding witnesses with firsthand knowledge of the secret negotiations Luna allegedly brokered.

The Trump administration has returned 23 Salvadorans accused of being gang members. One is César Humberto López, known as “El Greñas," or “Mophead," an MS-13 leader who had been expected to testify in federal court about a back-channel alliance with the Bukele administration. Luna helped create that alliance, U.S. prosecutors allege.

Bukele’s government arrested López in 2017, but a judge released him on procedural grounds in 2020. Four years later, Mexican officials captured and extradited him to the U.S. on terrorism charges. The Justice Department cited “sensitive and important" foreign- policy considerations for dismissing the charges against López in March.

The Justice Department didn’t respond to a request for comment.

Luna is a loyal enforcer whose political fate is tightly bound to the president’s, people who know him said. He was elected to El Salvador’s legislative assembly in 2018 and led the youth wing of GANA, the party that propelled Bukele to the presidency a year later.

With neatly gelled hair and a trimmed beard, he rallied support for Bukele on social media and television, echoing Bukele’s antiestablishment rhetoric about fighting corruption and the entrenched political elite.

One of Bukele’s first moves in office was to put Luna in charge of prisons. He helped orchestrate Bukele’s campaign to arrest suspected members of the MS-13 and 18th Street gangs en masse, transforming a country with the world’s highest murder rate into one of the safest in Latin America.

Now the Massachusetts-size country of 6.3 million has the world’s highest incarceration rate.

Close to 400 people have died in prison because of malnutrition and ill treatment, according to human-rights groups. Luna has said inmates typically die from poor health or old age.

Luna led campaigns to erase ubiquitous gang symbols, painting over graffiti-covered walls in slums and smashing headstones bearing the gang insignia of dead members. “We can’t allow a single terrorist symbol to be visible in any community around this country," he said in a TV interview.

The secret meetings arranged by Luna with jailed MS-13 leaders were aimed at reducing killings or murder statistics by making sure bodies of victims weren’t found, according to a Justice Department indictment against MS-13 gang leaders unsealed in 2023.

Luna also embezzled millions of dollars from El Salvador’s prison system, distributing paychecks to fake employees and directing most of the money to himself and his mother, Alma Yanira Meza, according to U.S. authorities. They also stole and resold pandemic-relief supplies, they said.

The indictment didn’t formally charge Luna. The State Department, which included Luna in 2021 on a list of corrupt Central American officials, didn’t respond to a request for comment. Luna’s mother couldn’t be reached for comment.

Among the inmates at El Salvador’s Terrorism Confinement Center are more than 300 alleged Salvadoran and Venezuelan gang members expelled by the U.S.

Luna’s continued presence in government after arranging the negotiations suggests he acted under Bukele’s instructions, said Luis Parada, a former military intelligence officer who ran as an opposition candidate in the 2024 presidential election in which Bukele was re-elected with more than 80% of the vote.

Luna was barred by the Treasury Department in 2021 from entering the U.S., having property and financial interests in the U.S., or conducting transactions with Americans under the agency’s authority to sanction individuals involved in corruption or serious criminal activity.

The negotiations led to a short truce that was broken after gangs killed almost 90 people over three days in March 2022, including dozens of small-business owners and working-class people who had been targets of extortion. The violence prompted Bukele to suspend civil liberties and due process. The legislative assembly has renewed the measures each month since then.

In recent years, El Salvador’s high court, dominated by Bukele allies, has blocked several U.S. extradition requests for top MS-13 leaders on procedural grounds.

MS-13 gang leader Élmer “El Crook" Canales-Rivera, who was extradited to the U.S. in 2023 after being captured in Mexico, is now one of the few high-ranking insiders beyond Luna’s reach who can testify about the secret negotiations in a U.S. court.

Write to Vera Bergengruen at vera.bergengruen@wsj.com and Santiago Perez at santiago.perez@wsj.com