For days after the killing of Alex Pretti by federal immigration officers in Minneapolis, fellow workers for the Department of Veterans Affairs held vigils at health centers nationwide, partly in protest and partly to pay their respects.

Becky Halioua, a recreational therapist and union leader at the Charlie Norwood VA Medical Center in Augusta, Georgia, said she felt “it was important to acknowledge him, as a brother of our organization.”

“It’s scary for me to think about a fellow VA employee being murdered by the same government that they work for,” Halioua told local TV station WRDW, a CNN affiliate, at the time. “That’s terrifying for me.”

Then Halioua learned she was under investigation by that same government. Her supervisor informed her that an internal probe had been launched into whether she violated agency rules regarding employee interviews with the news media, a probe that could result in disciplinary action.

Halioua is not alone, several sources familiar with the matter told CNN. At least three other VA employees have been investigated for their interactions with the press, including at least one other related to Alex Pretti, according to one of the sources.

As part of her investigation, Halioua says investigators emailed her photos of herself at the vigil from news coverage, which also included a brief interaction with a local newspaper. Someone had drawn a line around her image in some photographs, labeled with her name.

“It really gave me an uneasy feeling,” she says. Seeing her face circled in a photograph of a crowd seemed “very stalker-like.”

VA press secretary Quinn Slaven said he could not comment on Halioua’s case, citing privacy concerns. “Privacy laws prevent VA from publicly discussing specific details about its employees without their written consent,” Slaven said in a written statement. He did not address more general questions about the VA’s media relations policy and how often it conducts these types of investigations.

Federal agencies typically have rules that limit employees from talking about their government role or department in media interviews, while allowing them to speak in a personal capacity. In some cases, Trump administration officials have taken a hard line against federal employees talking with reporters and what they characterize as leaks.

In the case of the VA workers, the interviews touched on an issue that sparked a national discussion. Pretti’s killing, along with that of another protester, Renee Good, became political flashpoints in debates over immigration enforcement and free speech following a surge of Immigration and Customs Enforcement activity in Minneapolis in January.

Within hours of their deaths, officials from the Department of Homeland Security, which oversees ICE, claimed without evidence that Pretti and Good were domestic terrorists, sparking outrage. Protests and vigils, like the one Halioua attended, popped up across the country.

National Nurses United, a union that helped organize the January vigil for Pretti that Halioua attended, said its members won’t be silenced.

“It is despicable and immoral to come after any federal employee who participates in a vigil for a fellow worker,” the union said in a statement to CNN.

Halioua has added a grievance over the vigil probe to other complaints she’s filed with the Equal Employment Opportunity Commission against VA officials.

She believes she was investigated because of her role as a union leader and her participation in internal investigations against superiors. Halioua is a local president of the largest union of federal government employees in Georgia, the American Federation of Government Employees.

“I think that it’s a scare tactic,” she says. “I think that it is a method really to silence the employees with the loudest voices.”

A VA employee handbook published on its website says: “VA employees who are not authorized to speak officially on behalf of the Department should refer the media request to their administration communications office.”

It also says anyone not authorized to speak on behalf of the VA should make clear during media interviews about their opinion or other information, whether work-related or not, that they are speaking in their personal capacity.

Halioua says she didn’t coordinate with the VA because she was careful to only speak about her opinion, not in an official capacity for the agency, and because she attended the event off-hours and off the VA campus. She also said she didn’t wear her VA identification badge, or anything with a VA logo, on purpose.

“So that if there were any photos or anything like that that were taken, that it wouldn’t appear as though I was actively at work, or speaking in a VA capacity,” she said.

Halioua and another VA employee who was investigated, and who asked to remain anonymous for fear of reprisal, said they were asked similar questions about speaking to the media, including whether they had permission to do so.

The VA found that Halioua violated agency rules, she said, because she consented to an interview without requesting prior approval. It was recommended that her supervisor review the rules with her, and she’s asked if further disciplinary action will be taken.

“I very strongly believe that I have not violated those policies,” Halioua says.

Thomas Dargon, deputy general counsel for the AFGE union, says Halioua followed the rules of conduct and was exercising her first amendment rights at the vigil.

“It is disappointing to say the least that VA dragged her through an investigation,” he told CNN.

VA conducted internal investigations into employees who attended vigil for Alex Pretti | CNN Politics