When the Central Intelligence Agency was looking to quietly expand its operations in Mexico last year, it found an especially useful partner.
Mexico had tight restrictions on how freely U.S. forces could operate in the country. The nation’s president, Claudia Sheinbaum, had repeatedly said she didn’t want them taking part in operations on the ground in Mexico, asserting that it was a violation of her country’s sovereignty.
To the C.I.A., Guillermo Zuany Portillo, a prosecutor and former police commander in the border state of Chihuahua, offered a different kind of partnership.
He could pair C.I.A. officers with Mexican police units on counter-cartel operations — and he was in a bind that made him uniquely cooperative, Mexican and U.S. officials said.
Just months earlier, the United States had revoked Mr. Zuany’s visa because of his suspected ties to the very cartels the C.I.A. wanted to root out, according to a letter Mexican officials sent to the F.B.I. that was viewed by The New York Times.
And the C.I.A. wanted help going beyond the logistical support and intelligence sharing that Ms. Sheinbaum repeatedly said was the extent of the two countries’ security cooperation.
For more than six months, Mr. Zuany shepherded C.I.A. officers as they trained Chihuahua State forces, joined those forces on certain missions and provided expertise during ground operations, according to nine officials and law enforcement officers in Mexico and the United States. In return, officials said, Mr. Zuany’s U.S. visa was reinstated.
Then, in April, a truck carrying two C.I.A. officers drove off a cliff, killing all four passengers. The crash blew the C.I.A.’s cover in Chihuahua and set off a national scandal.
Mr. Zuany fled to the United States and is now under the U.S. government’s protection, according to U.S. and Mexican officials.
A Mexican investigation ruled the car crash an accident, but Mexican authorities this month issued a warrant for Mr. Zuany’s arrest on charges related to his involvement with the C.I.A. They then arrested his former boss, Chihuahua’s former attorney general, César Jáuregui, and charged him with treason, accusing him of also welcoming the agency into the state.
The charges revealed Mr. Zuany’s connection to the C.I.A. But the depth of his involvement with the agency and the fact that the C.I.A. began working with him while he was under active investigation by the F.B.I., as well as many of the details of the C.I.A.’s activities in Chihuahua, have not been previously reported.
This article is based on hundreds of pages of unreleased documents reviewed by The New York Times and interviews with two dozen Mexican and U.S. officials who spoke on the condition of anonymity to describe confidential operations and investigations.
The case shines a light on the Trump administration’s decision to expand the C.I.A.’s footprint in Mexico just as Ms. Sheinbaum was making clear, almost daily, that the presence of any U.S. security forces operating in Mexico would represent a grave violation of her nation’s sovereignty.
Privately, Ms. Sheinbaum has deepened security cooperation, including with the C.I.A. — in part to defuse President Trump’s threats of unilateral U.S. military action against the cartels. But her government has suggested that Chihuahua State officials like Mr. Zuany broke the law by allowing C.I.A. officers to operate without the authorization of the federal government.
Mr. Jáuregui, the detained attorney general, has denied knowledge of the C.I.A.’s presence in the state, instead blaming a state police commander who also died in the crash.
In text messages to The Times, Mr. Zuany said, “I have always conducted myself ethically and professionally.” He suggested The Times reporting was only getting “the version from people who are bitter and acting in bad faith.” He declined further comment.
The C.I.A. declined to comment.
Chihuahua’s Power Broker
Mr. Zuany has a reputation around Chihuahua. He is known to be well-connected and suspected to be corrupt, according to an arrest-warrant request from state prosecutors against Mr. Zuany, protected-witness complaints and more than a dozen state and federal officials in Mexico who know him.
Mr. Zuany “always made clear to us that he had all the power,” a Chihuahua police official said in testimony included in the arrest-warrant request. “He said nobody was ever going to remove him from his post because he knew lots of criminals,” the official added. “And that woe to whoever betrayed him.”
Four witnesses filed criminal complaints against Mr. Zuany saying he was an accomplice in the 2022 killing of two police officers and then worked to stall investigations into the deaths, according to a complaint seen by The Times. At least one of the witnesses later sought protection from the authorities, saying they had been told that Mr. Zuany had ordered their death, according to the witness’s formal protection request.
U.S. authorities later placed that person into witness protection, according to four people familiar with the arrangement.
Around 2025, the C.I.A. began working with Mr. Zuany, despite warnings about his history from at least one U.S. official and one Chihuahua State official, according to two people familiar with the conversations.
The C.I.A. used Mr. Zuany as a trusted contact on the ground but did not pay him like they do many informants, according to a person briefed on the relationship. While the U.S. military and State Department face strict legal restrictions on whom they can work with, the C.I.A. has a much freer hand and can work with people with checkered pasts who offer access to more significant targets.
The C.I.A. Arrives
In the fall of 2025, Mr. Zuany introduced an American C.I.A. officer to Chihuahua State police officers, according to four Mexican officials. Mr. Zuany told the group that he was there to build a new special forces unit, these people said.
For months, the American observed state agents practice tactical drills, analyzed their equipment and joined workouts, the four people said.
He and some other C.I.A. officers then began riding along on operations, usually alongside Mr. Zuany, according to the warrant request and six Mexican officials who witnessed them. In several cases, the operations ended in frustration when cartel targets got away, the officials said, raising suspicions among some Mexican agents that the criminals had been tipped off.
During one operation, Mr. Zuany and several Americans officers helped lead a mission to detain a cartel boss at a local bar, according to two Mexican officials who participated and two who were briefed. When Mexican forces arrived, the man and his crew were gone, visibly upsetting the Americans, these people said.
The Americans generally wore tactical gear and were armed during operations, though in several cases they wore jackets with Chihuahua State insignia, according to the warrant request and six officials who witnessed them. They frequently carried computers or tablets during operations for what appeared to be real-time information, according to the warrant request and the officials.
The C.I.A. officers did not engage in combat, but instead mostly appeared to provide intelligence and direction, often via Mr. Zuany, the warrant request and officials said.
On the way to one operation in March, Mr. Zuany and an American believed to be a C.I.A. officer discussed how to position state agents during the mission, a Chihuahua official told state prosecutors, according to the warrant request.
In another raid on a cartel safe house, an American officer used his rifle to provide cover from outside as Mexican agents entered, according to two Mexican officials who were present. Afterward, another C.I.A. officer went through digital devices that were seized and was present for the interrogation of a detainee, one of those officials said.
A Fatal Turn
In April, the C.I.A. had its biggest operation yet in Chihuahua: Locate and destroy a large meth lab in the remote mountains.
In the days before the mission, C.I.A. officers met with Mr. Zuany and other Chihuahua officials multiple times, according to the warrant request. Surveillance footage showed some of the C.I.A. officers carrying long guns in state offices, the request said.
Days later, four American officers joined a caravan of more than 60 Mexican security forces into the mountains, according to three Mexican officials who were present and the warrant request. During the two-day operation, the C.I.A. officers tried to conceal their identities by wearing balaclava-style masks, according to the officials present.
The C.I.A. officers helped the Mexican agents locate the meth lab, according to the warrant request and one person present. There was nobody in the lab when they arrived but it appeared to have been active recently, with gas tanks and vats of chemicals, the request said. Afterward, fatigued and hungry, the group departed for the overnight drive back to the state capital, according to the warrant request and Mexican investigative documents on the crash.
The nine-vehicle convoy wound along mountainous roads, led by an armored vehicle that kicked up dirt making visibility difficult, according to the investigation. The truck behind that armored vehicle carried two C.I.A. officers and two Mexican officials, the documents said.
After midnight, that truck drove off a cliff, plunged about 300 feet and exploded, killing the two C.I.A. officers and two Mexican officials, according to the crash investigation. Agents descended into the ravine to collect the bodies, the investigation said.
Mr. Zuany was not part of the operation, but Mexican agents called him from the scene, according to the warrant request and two people present. He instructed them to remove the C.I.A. officers’ bodies and ensure they were not wearing Mexican government insignia, the two people present said.
Mr. Zuany later pressured Mexican agents to conceal the C.I.A.’s presence in the operation when questioned by Mexican authorities, according to three people.
Ms. Sheinbaum expressed fury, saying her security cabinet didn’t know about the C.I.A.’s activities in Chihuahua State. She demanded answers from the Trump administration and state officials in Chihuahua, getting into a public war of words with Chihuahua’s right-wing governor, Maru Campos.
At the same time, Mr. Zuany and Mr. Jáuregui resigned.
Ms. Campos has maintained that she had no knowledge of the C.I.A.’s activities in the state. Immediately after the crash, her government suggested the police commander who died in the accident was responsible for bringing the C.I.A. along on police operations.
Mr. Zuany, in a text message, said that Ms. Campos actually did know about the C.I.A.’s presence. Ms. Campos said in a statement that Mr. Zuany is wrong and should be prepared to testify to a judge. “If he has something to say, he should come forward and say it,” she said.
This month, Ms. Campos and Ms. Sheinbaum met in Chihuahua. Both politicians said they raised their voices in a tense meeting. Shortly after, Ms. Campos’s government issued arrest warrants for Mr. Zuany and Mr. Jáuregui, accusing them of welcoming the C.I.A.
In a statement, Ms. Campos’ office said that the accusations against the two former officials represent “a serious failure” and that “she has taken responsibility for correcting the controls that made it possible.”
Mr. Jáuregui had been running to be the Chihuahua City mayor and was one of the state capital’s most prominent faces, plastered on billboards along many highways. Last month, on one of those highways, he was pulled over and arrested.
Mr. Zuany remains a fugitive.
Julian E. Barnes and Alan Feuer contributed reporting.
