Private Investigator Sentenced to Prison for Interstate Stalking and Harassment of Chinese Nationals on Behalf of the People’s Republic of China

Today, in federal court in Brooklyn, New York, Michael McMahon, 57, of Mahwah, New Jersey, was sentenced to 18 months in prison and ordered to pay an $11,000 fine for acting as an illegal agent of the government of the People’s Republic of China (PRC) and interstate stalking and conspiracy to commit the same, for his participation in a scheme to coerce repatriation of a U.S. resident to the PRC as part of its international repatriation effort known as “Operation Fox Hunt.” McMahon and co-defendants Zhu Yong, 68, of East Elmhurst, New York, and Congying Zheng, 29, of Brooklyn, were convicted by a federal jury in June 2023 following a three-week trial. In January 2025, Zhu and Zheng were sentenced respectively to 24 months and 16 months in prison.

As proven at trial, between approximately 2016 and 2019, the defendants and their co-conspirators participated in an international campaign to threaten, harass, surveil, and intimidate John Doe #1 and his family in order to force him and his wife, Jane Doe #1, to return to the PRC to face purported corruption charges. Beginning in 2012, John Doe #1 and Jane Doe #1 had been targeted for repatriation as part of the PRC’s transnational repression programs known as “Operation Fox Hunt” and “Operation Sky Net.” John Doe #1 and his family had accordingly sought to keep their address out of public records.

Zhu hired McMahon, a retired NYPD sergeant working as a private investigator, to locate John Doe #1. McMahon obtained sensitive information about John Doe #1, which he then reported back to Zhu and others, including a PRC police officer. McMahon also conducted surveillance outside the New Jersey home of John Doe #1’s relative and provided Zhu and PRC officials with detailed reports of what he observed. The operation was supervised and directed by several PRC officials, including a PRC police officer and a PRC prosecutor.

As McMahon knew, the operation was intended not only to locate John Doe #1, but to coerce him to return to the PRC by exerting pressure on his family members. In April 2017, PRC officials threatened to jail John Doe #1’s sister, who lived in the PRC, in order to coerce John Doe #1’s then-82-year-old father to travel from the PRC to their relative’s home in New Jersey. John Doe #1’s father, who had recently suffered a brain hemorrhage, was so frail that a doctor accompanied him for the trip. McMahon followed John Doe #1’s father from the relative’s New Jersey home, and, by doing so, was able to learn John Doe #1’s address. McMahon immediately provided this information to a PRC operative.

On Sept. 4, 2018, Zheng and another co-conspirator drove to the New Jersey residence of John Doe #1 and Jane Doe #1 – at the address that McMahon had provided – where they pounded on the front door, attempted to enter the house, and then peered through the windows in the back of the home. They left a note on the front door informing John Doe #1 that his “wife and children will be okay” if John Doe #1 surrendered himself to face a ten-year prison term in the PRC.

McMahon knew that the subjects of his investigation were wanted by the PRC government, a fact that he texted about with another investigator he contracted to help him. Following his arrest, McMahon acknowledged knowing that his employers wanted to get the victim back to China “so they could prosecute him.” After providing the victims’ address, McMahon told his surveillance partner that he was “waiting for a call” to find out what to do next. McMahon’s partner responded, “Yeah. From NJ State Police about an abduction,” to which McMahon responded “Lol.”  McMahon later suggested to a PRC co-conspirator that they “harass” John Doe #1 by “[p]ark[ing] outside his home and let[ting] him know we are there.” McMahon took other investigative steps designed to harass the victims, such as researching their daughter’s university residence and college major. McMahon was paid more than $19,000 in total for his role in the illegal repatriation scheme. In an apparent attempt to conceal the source, McMahon deposited payments from his PRC clients into his son’s bank account, the only time he had done so with client payments.

Previously, three co-defendants pleaded guilty in connection with their roles in the PRC-directed harassment and intimidation campaign. They are awaiting sentencing.

Sue J. Bai, head of the Justice Department’s National Security Division, U.S. Attorney John J. Durham for the Eastern District of New York, and Assistant Director Roman Rozhavsky of the FBI's Counterintelligence Division made the announcement.

The FBI New York Field Office investigated the case, with valuable assistance provided by the Department of State’s Diplomatic Security Service.

Assistant U.S. Attorneys Meredith A. Arfa and Irisa Chen for the Eastern District of New York and Trial Attorney Christine A. Bonomo of the National Security Division’s Counterintelligence and Export Control Section are prosecuting the case. Paralegal Specialist Rebecca Roth for the Eastern District of New York provided valuable assistance.

The FBI has created a website for victims to report efforts by foreign governments to stalk, intimidate, or assault people in the United States. If you believe that you are or have been a victim of transnational repression, please visit the FBI’s website.