Private Investigator Sentenced to 18 Months in Prison for Acting as an Illegal Agent of the People’s Republic of China

Earlier today, in federal court in Brooklyn, Michael McMahon was sentenced by United States District Judge Pamela K. Chen to 18 months in prison for acting as an illegal agent of the government of the People’s Republic of China (PRC), as well as for interstate stalking and conspiracy to commit such acts in connection with his participation in a scheme to coerce a U.S. resident to return to the PRC as part of its international repatriation effort known as “Operation Fox Hunt.”  McMahon and co-defendants Zhu Yong and Congying Zheng were convicted by a federal jury in June 2023 following a three-week trial.  As part of his sentence, McMahon was also ordered to pay a fine of $11,000.

John J. Durham, United States Attorney for the Eastern District of New York; Sue J. Bai, head of the Justice Department’s National Security Division; Terence G. Reilly, Acting Special Agent in Charge, Federal Bureau of Investigation, Newark Field Office (FBI); and Michael Alfonso, Acting Special Agent in Charge, Homeland Security Investigations, New York (HSI New York) announced the sentences. 

“McMahon, a former law enforcement officer who swore an oath to protect the public, went rogue and dishonorably engaged in a scheme at the direction of the People’s Republic of China, terrorized victims living in the New York metropolitan area, and shattered their sense of safety and security,” stated United States Attorney Durham.  “Thanks to the efforts of law enforcement, the defendants’ plan to coerce the victims to return to China failed, and the defendants have instead been brought to justice for their role in China’s insidious Operation Fox Hunt.  My Office remains unwavering in its commitment to exposing and undermining efforts by foreign governments to perpetrate transnational repression schemes that threaten our national security interests and harm individuals living in the United States.” 

Mr. Durham expressed his appreciation to the Department of State’s Diplomatic Security Service and the FBI’s New York Field Office for their work on the case. 

“Most private investigators operate within the bounds of the law and ethical conduct. McMahon knew exactly what he was doing—and at trial, we proved his knowing and willing participation in this scheme,” stated FBI Special Agent in Charge Reilly.  “His client, the People's Republic of China, has invested years and millions of dollars trying to silence dissent beyond its borders. When those efforts cross into our country, they threaten our national security.  The PRC needs to understand: we will not tolerate it.”

“This defendant allowed himself to become a partner in the PRC’s cruel harassment and intimidation campaign,” stated HSI New York Special Agent in Charge Alfonso.  “HSI, together with our federal counterparts, will continue to outfox our adversaries’ attempts to circumvent U.S. regulations, undermine national security, and target the American public.”

As proven at trial, between approximately 2016 and 2019, McMahon and his 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.

Yong 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 proven at trial, 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 September 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 hired 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 of payments from his PRC clients, McMahon deposited those payments into his son’s bank account, the only time he had done so with client payments.

Previously, in January 2025, Zhu and Zheng were sentenced respectively to 24 months’ and 16 months’ imprisonment.  Three additional co-defendants pleaded guilty in connection with their roles in the PRC-directed harassment and intimidation campaign.  They are awaiting sentencing.  Five co-defendants in the indictment, Hu Ji, Li Minjun, Tu Lan, Zhu Feng, and Zhai Yongqiang are fugitives.

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 https://www.fbi.gov/investigate/counterintelligence/transnational-repression.

The government’s case is being handled by the Office’s National Security and Cybercrime Section.  Assistant United States Attorneys Meredith A. Arfa and Irisa Chen are in charge of the prosecution, with assistance from Trial Attorneys Christine A. Bonomo and Scott A. Claffee of the National Security Division’s Counterintelligence and Export Control Section.  Paralegal Specialist Rebecca Roth also has provided valuable assistance.

The Defendants:

MICHAEL MCMAHON
Age: 57
Mahwah, New Jersey

ZHU YONG
Age: 68
East Elmhurst, New York

CONGYING ZHENG
Age: 29
Brooklyn, New York

E.D.N.Y. Docket No. 21-CR-265 (S-1) (PKC)