By Kara Scannell, CNN(CNN) — A Minnesota man was arrested and charged with impersonating an FBI agent after he tried to enter a federal jail and release suspected murderer Luigi Mangione, according to law enforcement sources. When officials with the Bureau of Prisons asked the man for his credentials, according to the complaint, the man provided a Minnesota driver’s license. The papers appeared to be related to legal claims against the Justice Department, according to the FBI agent who signed the complaint. Prison officials searched Anderson’s backpack, according to the complaint, and found a barbecue-style fork and a circular steel blade. He is facing federal and state murder charges and has pleaded not guilty.