In an unusual incident at New York City's Metropolitan Detention Center, a man claiming to be an FBI agent arrived on site on the evening of Wednesday, attempting to secure the release of Luigi Mangione, a high-profile detainee currently held at the facility.
The individual, identified as Mark Anderson, 36, originally from Minnesota and with a criminal background including drug-related offenses, was taken into custody at the scene. Officials subsequently charged him with impersonating a federal officer following what was described as a failed effort to free Mangione, who is awaiting trials on state and federal murder charges related to the killing of UnitedHealthcare CEO Brian Thompson.
Although the criminal complaint did not name the detainee Anderson sought to release, a law enforcement source familiar with the case confirmed that the target was Mangione. This source requested anonymity due to the sensitivity of the matter.
During Anderson’s federal court appearance in Brooklyn on Thursday, he was held without bail and did not enter a plea. Court records and detention center data confirm he has since been incarcerated at the Metropolitan Detention Center, the same facility where Mangione is housed.
Prior legal documents submitted by Anderson reveal that he has a history of mental health issues and disclosed last year that he suffers from multiple disabilities related to mental illness, which have led to his classification as fully disabled by the Social Security Administration. He has reported relying on state and federal assistance and a lack of financial resources.
Publicly available records indicate Anderson's extensive history with the criminal justice system, including numerous arrests and convictions connected to drug and alcohol offenses in his home state of Minnesota and neighboring Wisconsin. Additionally, he faces ongoing legal matters in the Bronx, including an accusation of brandishing a firearm.
The details of the incident at the detention center describe Anderson arriving around 6:50 p.m., presenting himself to intake officers as an FBI agent with purported judicial authorization to release a particular detainee. However, when asked for valid credentials, he instead presented a Minnesota driver's license, aggressively handed over documents, and claimed to possess weapons.
An FBI agent reviewing the documentation identified them as materials related to claims against the Justice Department rather than official court orders. Upon searching Anderson's belongings, officers found a barbecue fork and a small circular steel blade, appearing to be a pizza cutter, suggested as potentially weaponized items.
Anderson’s Minnesota license lists an address in Mankato, about 65 miles from Minneapolis. Having relocated to New York for employment, he initially secured a position at a Bronx pizzeria, which fell through. Records show that since at least 2023, his residences in New York have included hotels, shelters, and an apartment in the Bronx.
He has filed multiple handwritten lawsuits in which he represented himself, targeting the Pentagon, diplomatic representatives from China and Russia, and a Minnesota police department; these suits have been dismissed. However, a lawsuit alleging unpaid overtime by a Bronx pizzeria remains active.
The incident adds complexity to Mangione's ongoing legal matters. Shortly before Anderson's arrest, the Manhattan district attorney's office pushed for a July 1 trial date in Mangione’s state case. Additionally, Mangione is scheduled for a federal case conference on Friday, where a judge is expected to decide soon on whether prosecutors may pursue the death penalty and introduce certain evidence.
Federal trial preparations include jury selection planned for early September, with the possibility of the main trial occurring later in the year or early 2025, contingent on the death penalty decision.
Mangione, a 27-year-old Ivy League graduate hailing from a wealthy Maryland family, denies the charges in both cases. The state-level charges carry potential life imprisonment. His case has garnered notable public interest, particularly from advocates critical of the health insurance industry, some of whom attend court hearings wearing green — a reference to the Luigi character from Mario Bros. — and bearing slogans supporting Mangione.
The victim, Brian Thompson, aged 50, was fatally shot in December 2024 while en route to an annual investor event for UnitedHealth Group in midtown Manhattan. Surveillance footage captured a masked gunman firing from behind, with investigators noting inscriptions on the ammunition allegedly alluding to insurance claim avoidance strategies.
Following his arrest five days after the shooting at a McDonald’s in Altoona, Pennsylvania, Mangione underwent preliminary court proceedings and was transported to New York’s Metropolitan Detention Center.
The facility also houses other notable detainees, including the former President and First Lady of Venezuela. Its former inmates have encompassed high-profile figures from the entertainment industry and the business sector.