Brian Hastings, a top Border Patrol official, stared grimly at the television cameras.

It was July 1, 2019, and Hastings was facing down a scandal: News reports had revealed that Border Patrol agents were posting wildly offensive comments and memes in a secret Facebook group.

Agents had shared crudely manipulated images of men sexually assaulting Rep. Alexandria Ocasio-Cortez, a New York Democrat and frequent antagonist of the Border Patrol; joked about migrants who died while trying to enter the United States; and made racist insults about Central Americans. The group called itself “I’m 10-15,” Border Patrol radio code for “aliens in custody,” and included some 9,500 current or former agents.

Critics of the agency — already concerned about the separation of migrant families and deplorable conditions in detention facilities — saw the vulgar Facebook posts as further evidence that a culture of casual racism and misogyny was festering within the Border Patrol.

On national TV that day, Hastings vowed that any agent who engaged in online misconduct would be held accountable. “We take all of the posts that were put out today very seriously,” said Hastings, who was then the chief of law of enforcement operations for the patrol and now oversees the Rio Grande Valley sector. “Each one of these allegations will be thoroughly investigated.” The internal affairs unit of Customs and Border Protection, the agency that oversees the Border Patrol, had already opened an investigation, he said.

Within days, the horrified leaders of the powerful House Committee on Oversight and Reform announced a separate probe of the group, whose existence was first exposed by ProPublica.

But now, more than a year later, after one of the most sweeping internal investigations in the history of the agency, CBP has provided little new information about “I’m 10-15” or its efforts to address toxic attitudes within the ranks. Instead, it has released a basic summary of its findings. The agency has not said who was behind the group or its most egregious posts. And it has not explained how such a group — whose members included Carla Provost, then the highest-ranking official in the Border Patrol — had existed for nearly three years without any sort of intervention from patrol brass.

And in Congress, the oversight committee said its work has been derailed by a lack of cooperation from CBP leaders, who have refused to provide congressional investigators with the names of employees who made offensive posts or even identify the agents who’ve been disciplined.

“More than a year after the existence of the group was reported, CBP continues to obstruct a congressional investigation into the results of the agency’s findings, blatantly shielding agents that have dehumanized immigrants and fostered a culture of cruelty and violence,” said Rep. Veronica Escobar, a Democrat representing El Paso, Texas, who was mocked by agents in “I’m 10-15” posts.

Last month, the agency told the Los Angeles Times that it had investigated 138 employees, eventually deciding to fire four of them, suspend 38 without pay and issue warnings or reprimands to more than two dozen. CBP investigators cleared 60 agents of any wrongdoing.

But CBP has not revealed the exact offenses that led to this wave of firings and other sanctions, nor has it disclosed the key facts — such as name, rank or location — about the employees who’ve been disciplined. Such information could reveal troubling clusters of agents or supervisors at a particular station and whether the terms of the discipline were appropriate. The agency has long maintained that it is barred by federal privacy law from identifying employees who’ve been found guilty of misconduct, and it typically does not disclose the names of front-line Border Patrol agents.

In response to questions from ProPublica about the terms of the suspensions it has imposed, a CBP spokesperson would only provide general answers. “We are not able to share specific details, however, suspensions generally range from three to 14 days,” the spokesperson said.

Under the terms of the Border Patrol’s union contract, suspensions of up to 14 days are considered relatively minor punishment, while those that extend beyond two weeks are deemed to be more serious.

While CBP has not named the employees it fired, Border Patrol sources said that one of those who was ousted is Waldemar Ortiz, an agent who worked at the station in Deming, New Mexico. The sources requested anonymity because they had gone outside of the official chain of command to share information.

A former U.S. Marine, Ortiz posted comments suggesting that Border Patrol agents lock undocumented migrants in shipping containers, according to The Intercept, which obtained a huge trove of content from the Facebook group. The specific actions that led to the agent’s ouster remain unclear.

One source said Ortiz, who has enlisted the support of the National Border Patrol Council, the union representing the nation’s roughly 20,000 Border Patrol agents, could potentially win his job back at an upcoming arbitration hearing. Ortiz did not respond to a request for comment from ProPublica, nor did union President Brandon Judd.

The union has condemned the offensive Facebook posts, saying the “inappropriate content” is not representative “of our employees and does a great disservice to all Border Patrol agents, the overwhelming majority of whom perform their duties honorably.”

ProPublica has not learned the names of the other three employees who’ve been fired or whether they’ll be appealing their firings.

At an unrelated court hearing last year in San Francisco, an attorney for CBP, Laura Myron, argued that documents identifying Border Patrol agents accused of misconduct should not be released to the public. Citing several federal court rulings, Myron told a panel of 9th Circuit judges that government agencies are obligated to protect the privacy of “individual government employees, especially those at a lower level.” (The hearing centered on efforts by the ACLU to obtain Border Patrol disciplinary records through the Freedom of Information Act.)

While CBP has turned over two large batches of documents to the House oversight committee, names and other key information were blacked out, limiting the usefulness of the records, a committee aide told ProPublica. It’s unclear why the dispute between CBP and Congress has dragged on for so many months, since congressional committees frequently receive sensitive — even classified — information from executive branch agencies.

“They are obstructing our investigation by refusing to lift redactions and hiding the names and roles of CBP employees, as well as their conduct,” said the aide. “This severely limits our ability to conduct oversight and determine whether the specific employees who made these threatening and repugnant posts continue to work for CBP in positions of power over immigrants and children.”

On July 20, the committee chair, Rep. Carolyn Maloney, a Democrat from New York, posted one of the redacted documents online. It’s a three-page “last chance agreement” between Border Patrol officials and an agent who was apparently involved with the Facebook group. The record — which resembles a plea deal from a criminal case — shows that CBP leaders initially recommended that the agent be fired. In the end, though, the agent was suspended from duty for seven days for unprofessional conduct and another charge.

From the document, it’s impossible to determine the nature of the agent’s violation, which patrol commander decided to spare the agent’s job or where the agent is stationed.

Asked about the committee’s claims, a CBP spokesperson would only say that the agency “continues to provide documents to the committee” as disciplinary cases are investigated and closed.

Congressional investigators initially requested interviews with 11 Border Patrol employees, including Provost, the former chief; Rodney Scott, the current chief; and the head of the Laredo sector, a key region in South Texas. However, the impasse over records has led the investigators to cancel all interviews, the committee aide said. The committee has not said why it wanted to interview the 11 employees.

Provost has said she was not aware of the offensive posts and seldom visited the Facebook group.

“I’ve yet to see management and higher officials in D.C. be held accountable for what happened,” said one Border Patrol agent, who asked to remain anonymous because they were not authorized to speak to the media. “You’re telling me they didn’t know what was going on in the Facebook group? I don’t believe it.”