Allison Guerriero, 52, the mistress of former FBI counterintelligence agent Charles McGonigal, died suddenly on Thursday evening at her home in Boynton Beach, Florida. Her death occurred hours after she posted a series of messages on X, formerly Twitter, including a video in which she called for attention to other FBI agents and stated, "I hate the FBI."
Guerriero had been engaged in a years-long public campaign against McGonigal, 58, and other senior figures within the FBI. McGonigal, the former special agent in charge of the FBI's counterintelligence division in New York, is currently serving a six-year prison sentence for secretly working for Russian oligarch Oleg Deripaska. Guerriero had publicly stated that she believed McGonigal, whom she called a "traitor," deserved a harsher sentence.
Her father, Bill Guerriero, 80, told the Daily Mail that the cause of death has not yet been determined and that the family is awaiting the autopsy report. "We really don't know yet. We're waiting to get access to the autopsy report. I believe they're going to issue a death certificate within the next day so we can get her home and have her put to rest," he said. He added, "It could have been an accident. She could have slipped. It could have been anything."
The Boynton Beach Police Department responded to Guerriero's apartment on Thursday evening. A police spokesperson indicated that "there do not appear to be any signs of foul play at this time," but that an investigation is ongoing. Police are awaiting information from the medical examiner's office.
Roger Stone, a conservative lobbyist and ally of former President Trump, with whom Guerriero was also close, stated that he had exchanged texts with her on the day of her death and that she seemed to be in "excellent spirits." He described her as a "brilliant researcher and writer" with a "wide network of contacts."
Stone dismissed the possibility of suicide, saying, "There's no doubt that she would never take her own life. She was too devout a Roman Catholic. She would never do that." He also noted that Guerriero had overcome significant health challenges, including cancer and injuries from a fire. He acknowledged that she remained "extremely aggravated" that McGonigal had not faced charges of treason.
While some sources suggested Guerriero had faced online threats due to her public statements, her father expressed skepticism about any suspicious circumstances surrounding her death. "She showed no concern that there was anyone trying to harm her or anything like that. I really don't think there was anything suspicious, not from what I know about this," he said. He added that she had appeared happy and healthy since moving to Florida three years prior.
Guerriero met McGonigal in the spring of 2017 while volunteering for a charity. Their relationship, which lasted about 18 months, ultimately led to her providing information to the FBI that contributed to his downfall. She stated that McGonigal had told her he was going through a divorce from his wife, Pamela, which she later discovered was not true.
In October 2017, McGonigal allegedly received $80,000 in cash. Guerriero later found the money in their shared apartment and, after challenging McGonigal, he claimed he had won it gambling. Their relationship ended on Christmas Eve 2018, shortly after McGonigal retired from the FBI. Guerriero began sharing her suspicions with the FBI in 2019, ultimately contributing to McGonigal's arrest in January 2023.
Ken Kurson, a journalist and political consultant, described Guerriero as "loyal, chaotic, irreplaceable, occasionally even brilliant," and stated he was "bereft" by her death. Guerriero had previously worked as a vice president of US operations for an Israeli security firm.