Mark Anderson, 36, of Minnesota, was arrested at the Metropolitan Detention Center in Brooklyn, New York, after allegedly impersonating an FBI agent in an attempt to secure the release of Luigi Mangione, who is accused of the fatal shooting of UnitedHealthcare CEO Brian Thompson. The incident occurred on a recent Wednesday night. Concurrently, pre-trial hearings continue in Mangione's murder case, revealing details about his December 2024 arrest and evidence that the defense seeks to exclude.
Mark Anderson Arrested Impersonating FBI Agent in Brooklyn
Arrest and Charges at Metropolitan Detention Center
On Wednesday night, Mark Anderson arrived at the Metropolitan Detention Center in Brooklyn, New York, approaching the jail intake area around 6:50 p.m.
He reportedly informed officers that he was an FBI agent and possessed a court order for the release of an inmate, identified as Luigi Mangione.
When asked for federal credentials, Anderson presented a Minnesota driver's license. He also claimed to have weapons in a bag. During the encounter, Anderson displayed and threw various documents at Bureau of Prisons (BOP) officers. These papers reportedly appeared to be related to filing personal claims against the United States Department of Justice.
Following his statements, correctional staff confiscated Anderson's bag. A search of the bag revealed a barbecue fork and a circular steel blade, which was described as resembling a pizza cutter.
Anderson, 36, was subsequently charged with impersonating a federal officer. He was ordered held without bail after an initial appearance in Brooklyn federal court and is currently incarcerated at the same Metropolitan Detention Center where the incident occurred.
Background of Mark Anderson
Anderson, a Minnesota native, is 35 or 36 years old according to various reports. He has a reported history of drug-related and other arrests in Minnesota and Wisconsin. Court papers from the previous year indicate he disclosed suffering from mental illness and is considered fully disabled by the Social Security Administration.
Anderson has also filed multiple handwritten lawsuits against various entities, including the Pentagon and foreign ambassadors, which have been dismissed. He had moved to New York for a job opportunity that did not materialize and had been employed at a Bronx or New York pizzeria prior to his arrest.
Luigi Mangione Murder Case: Pre-Trial Hearings and Public Support
Case Overview and Federal Charges
Luigi Mangione, 27, has been held without bail at the Metropolitan Detention Center in Brooklyn since his arrest on December 9, 2024. He is accused in the fatal shooting of UnitedHealthcare CEO Brian Thompson. Thompson was shot on December 4, 2024, in midtown Manhattan. Police reports indicated that ammunition used in the shooting had phrases such as "delay," "deny," and "depose" written on it, echoing language associated with insurance claims.
Mangione has pleaded not guilty to both state and federal murder charges. His federal charges include two counts of stalking, one count of murder, and one count of using a firearm to commit murder. The charges carry the possibility of the death penalty. In April, U.S. Attorney General Pam Bondi announced the government's intent to seek the death penalty against Mangione, describing the act as "political violence" and a "premeditated, cold-blooded assassination."
Federal prosecutors have also argued in an August filing that Mangione poses a threat to the public, alleging he actively seeks to influence others to adopt violent methods for ideological or political objectives. Prosecutors state that since the murder, some individuals identifying as Mangione's supporters have increasingly viewed violence as an acceptable substitute for reasoned political disagreement.
Jury selection for Mangione's federal case is reportedly scheduled for September 8.
Details of Mangione's December 2024 Arrest
Mangione's arrest on December 9, 2024, followed a five-day search after the shooting. He was apprehended at a McDonald's restaurant in Altoona, Pennsylvania. Testimony during recent pre-trial hearings revealed that a customer tip initiated the arrest. A McDonald's employee reported a patron resembling the suspect, noting he wore a black hoodie, a medical mask, and a tan beanie, and had visible eyebrows.
Body camera footage released by prosecutors and played in court depicted Mangione inside the McDonald's, consuming a meal while officers maintained positions around him awaiting additional personnel. Lieutenant William Hanelly testified that an officer initially responded to the tip with sarcasm, considering it improbable the New York City suspect would be in Altoona. However, officers at the scene noted a resemblance to images circulated by the New York Police Department.
An officer was reportedly heard stating in a phone call, "It's him. I'm not kidding. He's real nervous. It's him."
Police body camera videos documented Mangione's interactions with officers on December 9, with background Christmas music audible. When officers first approached Mangione, they requested he lower his mask, which he complied with. He provided the name "Mark Rosario" and presented a New Jersey identification card that police later determined to be false.
Lieutenant Hanelly stated that the false identification provided probable cause for Mangione's arrest. In the footage, Mangione is heard disclosing his real first name, Luigi. Another body camera video shows an officer informing Mangione he was under investigation for providing false identification, after which Mangione was seen placing his hands on a wall as officers placed him under arrest. A photograph of Mangione with his hands behind his back was taken after the arrest.
Pre-Trial Proceedings and Contested Evidence
Current pre-trial proceedings focus on the defense's efforts to exclude certain evidence from the upcoming trial, which has not yet been scheduled. This evidence includes a 9mm handgun and a notebook recovered from Mangione's backpack during his arrest, as well as statements he made to law enforcement officers.
Defense lawyers argue that officers lacked a warrant to search the backpack. Prosecutors allege that the notebook contained writings by Mangione regarding "the deadly, greed-fuelled health insurance cartel." Lieutenant Hanelly testified that exceptions for warrants exist. Officer Christy Wasser, who searched the backpack, was questioned by the defense regarding the basis for the search and responded, "No, we search everyone," when asked if the search was conducted because she believed he was the New York City shooter.
Prosecutors also presented notecards, attributed to Mangione, which reportedly listed post-shooting tasks, with one card including the instruction: "Change hat, shoes, pluck eyebrows."
Public Response and Support for Mangione
Mangione's case has drawn public and media attention.
Since his arrest, his legal defense fund has reportedly raised over one million dollars in donations from individuals expressing discontent with the nation’s for-profit medical system.
He has also received letters, photographs, and books at the federal facility where he is held. Mangione has attracted supporters who often attend his court appearances, wearing green clothing and carrying signs with slogans such as "Free Luigi."