The FBI on Thursday arrested a man on a charge of stalking former Trump administration adviser Katie Miller, an administration official familiar with the investigation told NBC News.

John Anthony Proia III, 41, was arrested and charged with stalking over allegations that he called, texted and left voicemails with “disturbing messages” about the victim, who was described as a former political adviser, and her husband, who is currently a high-level federal government employee, the Justice Department said in a news release.

The Justice Department did not name Katie Miller, though an administration official familiar with the investigation confirmed to NBC News that the victim is Miller, who is married to White House deputy chief of staff for policy Stephen Miller and hosts a popular conservative podcast.

“Thank you Todd Blanche, Leah Foley, and the Washington Field Office,” Miller wrote in a post on X on Thursday, referring to Attorney General Todd Blanche and U.S. Attorney Leah Foley.

Proia was indicted by a federal grand jury in Boston on Thursday on one count of cyberstalking after being arrested earlier in the day. He allegedly contacted the former political adviser more than 40 times over the course of less than two months, according to the Justice Department.

The defendant also allegedly sent disturbing messages to Miller’s parents during the August 2026 to September 2026 time frame cited in court documents.

“As alleged in the Indictment, the defendant repeatedly and relentlessly targeted the victim, her husband and her family with deeply disturbing communications that profoundly disrupted their lives,” Foley said in a statement.

Ted Docks, special agent in charge of the FBI’s Boston Division, wrote in a statement on Thursday that Proia was arrested “for allegedly engaging in a sustained campaign of harassment to frighten this victim and her family, inflicting significant emotional distress.”

Proia made the calls, sent text messages and left voicemails from “an ever-changing series of unfamiliar phone numbers” to Miller, who lives in the Washington, D.C., area, the DOJ said.

The department added that those phone numbers were obtained through applications that provide free phone numbers for calling and messaging via Voice over Internet Protocol. The applications allow a user to hide their identity and easily generate new phone numbers, according to court filings.

According to court documents, Miller sometimes received multiple communications from Proia in one day, including calls made late at night. Miller did answer some of the calls, but Proia also left voicemails, the DOJ said.

The calls “were allegedly made by what appeared to be a male caller employing a menacing tone and often using expletives,” the Justice Department said.

The Justice Department also detailed some text messages sent to phone numbers associated with Miller’s parents.

In one message, Proia allegedly wrote to Miller’s mother, calling Stephen Miller “evil” and Katie Miller a “creature.” Another message allegedly featured a photo of Katie Miller, while another read, “My god, how can you be proud of this filth?”

In a text message to the victim’s father, Proia allegedly wrote, “Hey [first name of victim’s father], how goes it? Hope your daughter marrying a Jewish Nazi/white supremacist is working out for you and [first name of victim’s mother]. Did you raise her to be trash or did that just happen naturally?”

Proia’s arrest comes after Bloomberg reported over the weekend that two senior FBI officials in Washington were demoted and reassigned to FBI headquarters due to concerns that the agency was not moving efficiently enough to investigate threatening phone calls made to Miller, three people familiar with the matter told Bloomberg.

Darren Cox, the agency’s Washington Field Office’s assistant director in charge, said in a statement to Bloomberg that the move was a personnel decision made at the field office level based on “our constant evaluation of mission needs.”