Massachusetts Man Arrested in Katie Miller Cyberstalking Case

John Anthony Proia III, 41, of Waltham, Massachusetts, was arrested and indicted Oct. 1, 2026, in Boston on one federal count of cyberstalking. Prosecutors allege that from Aug. 3 to Sept. 23, 2026, he contacted the victim more than 40 times using ever-changing VoIP numbers and sent disturbing messages to her parents. Officials confirmed the victim is Katie Miller, wife of White House deputy chief of staff Stephen Miller; the indictment does not name her. Proia was due in court at 5 p.m. Thursday. His lawyer did not immediately respond. U.S. Attorney Leah Foley said the defendant "repeatedly and relentlessly targeted the victim, her husband and her family with deeply disturbing communications that profoundly disrupted their lives." Ted Docks said Proia allegedly ran a sustained campaign of harassment to frighten the victim and her family. Todd Blanche posted on X, "This behavior is criminal and will be treated as it should - with prosecution!" Katie Miller thanked Blanche, Leah Foley, and the Washington Field Office. Two FBI Washington Field Office counterterrorism officials were demoted and reassigned, first reported by Bloomberg Law; Darren Cox cited "our constant evaluation of mission needs." A prior state probe of Barbara Wien over Wanted posters near the Millers' home ended after Parisa Dehghani-Tafti wrote that "nothing in the proceeds of the search warrant supports criminal prosecution."