The revelations over secret Facebook groups popular with Border Patrol agents were eye-popping. A constant stream of racist, sexist and violent images persisted for years, reporters revealed. Days later, officials said those responsible for posts were previously investigated, with unclear results.

Then, in testimony Wednesday, Border Patrol Chief Carla Provost acknowledged that she was a member of one of the groups; she had been active since at least last fall, according to images published by the Intercept.

She was involved in the group to evaluate “how I am representing my workforce,” she told lawmakers at a hearing about oversight within her agency.

Provost sighed deeply. “I didn’t think anything of it at the time,” she told the House Appropriations subcommittee, and said she was unaware of the nature of the posts until ProPublica published a report on July 1. The posts contain caustic remarks about the deaths of migrants, sexually explicit images and xenophobic comments.

Her admission raised a question: Why did she not use the group instead to measure cultural sentiment among agents, attitudes about migrants or possible concerns she could address at the top?

“She either missed it from failure to effectively do her job or actively avoided thinking about it,” Josiah Heyman, director of the Center for Inter-American and Border Studies at the University of Texas at El Paso, said Thursday.

Part of Provost’s duties is to visit agents at Border Patrol facilities, where front-line supervisors may play down realities of a recruiting and morale crisis. Facebook, then, could provide an unvarnished look at how agents view themselves and their duties — or, in this case, reveal cultural issues that rise to the surface as the agency faces intense scrutiny.

Provost looked for candid words about her performance, Heyman noted, “but she manifested no curiosity about candid things being said in other regards.”

More than 60 active and eight former agents are being investigated for their involvement in the group, the Associated Press reported. Some posts questioned the authenticity of a photo of a drowned migrant man and his young daughter.

Another showed a crudely doctored photo of Rep. Alexandria Ocasio-Cortez (D-N.Y.) performing forced oral sex on President Trump.

Customs and Border Protection, the agency that includes Border Patrol, did not respond to a request for comment about why Provost did not use the group in a manner that could have prevented the organization’s latest black eye.

In her testimony, Provost said she is “as outraged as everyone else.”

She “condemned” the posts in a message to the agency, opened investigations of agents who posted or responded to posts, and gave her passwords to agency oversight officials, who analyzed her online activity and told her that she had logged on to Facebook nine times over the period of a year and that her interactions had been mostly with friends and family members.

Yet Provost said the posts at the private group page “I’m 10-15,” after the law enforcement code for “aliens in custody,” were not indicative of cultural rot within Border Patrol. She called offenders “a few bad apples” among about 20,000 agents. The group for current and former agents included about 9,500 members, although other groups exist.

Heyman suggested that the posts indicate cultural and attitudinal problems that he said officials have been reluctant to address. He led a survey of about 1,100 migrants deported to Mexico, and nearly a quarter of respondents said they were verbally abused by U.S. immigration agents, primarily Border Patrol members. Eleven percent reported physical abuse.

“The posts are very consistent with that we found,” Heyman said. “It’s not just, ‘This person is out of status, and I need to apply law’ . . . but, 'I hate this person, I want to humiliate this person.’ ”

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