A man accused of impersonating a federal agent in a bid to allegedly free Luigi Mangione, the man accused of gunning down the CEO of United Healthcare in 2024, has been arrested. Mark Anderson, 36, is accused of going to the New York jail where Mangione is being housed and allegedly posing as an FBI agent, a criminal complaint states. He allegedly said he had paperwork that had been signed by a judge to free the accused killer. Though the complaint does not name Mangione, a law enforcement source told the BBC that Anderson allegedly sought to free him. Anderson appeared before a judge on Thursday but has not entered a plea. The BBC has contacted an attorney said to be representing him. Anderson approached the intake area of the Metropolitan Detention Center in Brooklyn on Wednesday and is accused of telling officers that he was an FBI agent. When officers asked him for credentials, Anderson provided a Minnesota driver's license, claimed to be in possession of weapons, and displayed and threw what authorities described as numerous documents at jail staff. Bureau of Prisons officials detained Anderson and searched his bag, where they found a large barbeque type fork and a tool resembling a pizza cutter. He had traveled to New York City for a job opportunity from Mankato, Minnesota, and had been working at a local pizzeria. Anderson is facing a charge of impersonating an officer. Mangione has been held at the Brooklyn jail since 2024, accused of both state and federal charges in the killing of United Healthcare CEO Brian Thompson, for which he has pleaded not guilty. The case has sparked considerable public interest and discussion about healthcare costs in the U.S.