A federal gun charge has been added against a U.S. Postal Service employee who allegedly fired into the Minneapolis Federal Reserve Bank building during a July fireworks display and at whose home police later found anti-government literature.

Prosecutors added charges of "possession with the intent to use a firearm in a federal facility during the commission of a crime" against Christopher Douglas Wood, 43, of St. Paul, who was first arrested on state charges in August.

Wood, who joined the Postal Service in 1998 and most recently worked as a mail processing clerk at the downtown post office, is accused of firing three shotgun blasts at the Reserve building across the street from the Minneapolis Central Post Office's parking ramp at 100 1st St. S. after his shift ended on July 21.

According to earlier charges filed in Hennepin County District Court, several Reserve employees were inside the building when Wood allegedly fired into it, causing more than $40,000 in damage to the building. Hundreds of people were also on the street outside watching the Aquatennial fireworks display.

Wood was on administrative leave at the time of his August arrest. No update was available Monday by the U.S. Postal Service Office of Inspector General, which investigates crimes committed by postal employees.

Police in August raided Wood's St. Paul apartment and found a 12-gauge shotgun and ammunition, literature referencing the "End the Fed" movement and counterfeit bills bearing the likeness of former U.S. Rep. Ron Paul. Investigators also found an item related to 9/11 conspiracies in Wood's car and described recent Facebook posts that included references to "fastest firing shotgun" and "Lucifer-Obama," according to a state search warrant.

The federal charge against Wood is outlined in a federal charging document that typically precedes a guilty plea. An attorney for Wood declined to comment Monday on the new charges, which also seek to forfeit a Mossberg shotgun and ammunition seized from Wood's apartment.

Woods is scheduled for an initial appearance before Chief U.S. District Judge John Tunheim on Dec. 17. Hennepin County charges of first-degree property damage and reckless discharge of a firearm are also still pending against Wood, and he has an omnibus hearing scheduled in that case on Dec. 28.

Twitter: @smontemayor