When police raided Christopher Wood’s St. Paul apartment, they found a 12-gauge shotgun stashed underneath his bed and an assortment of ammunition. They also discovered literature referencing the “End the Fed” movement, and a stack of counterfeit bills featuring the face of retired U.S. Rep. Ron Paul, whose book of the same title was released in 2009, according to court filings.

If Wood had a motive for his bizarre shotgun attack on the Minneapolis Federal Reserve Bank building last month, it probably lies there, police say.

Officials on Friday confirmed that Wood, who joined the Postal Service in 1998 and most recently worked as a mail processing clerk at the downtown post office, is on administrative leave.

“I can tell you that Mr. Wood is on non-duty status, which basically means he’s not working at this time,” said deputy Special Agent in Charge Jeff Krafels for the U.S. Postal Service Office of Inspector General, which investigates all crimes committed by postal employees.

He declined to elaborate on whether Wood could also face federal charges, citing the ongoing investigation.

“We can elect to file state or federal charges, and right now Minneapolis PD put on the state charges, so that doesn’t mean down the road something can’t change,” he said.

State charges were filed earlier this week against Wood, 43, who prosecutors believe went to the top of the Minneapolis Central Post Office’s parking ramp at 100 1st St. S. after his shift ended on July 21 and fired three shotgun slugs at the Reserve building across the street. The slugs “punched through fascia, broke windows, smashed through interior walls,” before landing in office space, the filing said. Damage was estimated at $40,242.

Court records show that Wood’s only prior brushes with the law were for minor traffic violations. Efforts to reach Wood’s attorney were unsuccessful.

A criminal complaint filed in Hennepin County District Court says that at the time of the incident there were several Reserve employees in the building, which is staffed 24 hours a day, seven days a week, and hundreds of people on the street outside watching the Aquatennial fireworks display.

Two Federal Reserve security officers reported hearing three loud blasts from near the top of the post office ramp, and investigators later used a laser device to trace the trajectory of the shotgun slugs to a spot near where Wood parks his car.

In addition to the “End the Fed” memorabilia seized from his apartment, investigators also found an item related to 9/11 conspiracies in the trunk of his car, according to a search warrant. A Minneapolis detective who reviewed Wood’s Facebook account categorized his recent posts as referencing topics from “fastest firing shotgun” and “tax” “to “Lucifer-Obama,” the warrant said.

Surveillance footage from the day before showed Wood pulling into his parking spot at the ramp about 3:16 p.m., nearly 45 minutes before the start of his shift, and later firing off a homemade gun made from a PVC pipe, according to the complaint. Several Reserve employees later told investigators that they saw Wood loading items into the PVC gun while wearing surgical latex gloves, police say.

Cameras again captured Wood coming and going from the ramp on July 21, although his car was not seen leaving until 11:15 p.m., even though his shift had ended at 10.

In a statement released Friday, Reserve officials said they had stepped up security around the building.

“While we have no evidence of an ongoing threat to our employees or visitors, safety is our number one concern, and Federal Reserve law enforcement has increased security measures and will continue to be vigilant,” the statement read.

Wood was arrested Monday by members of the Minneapolis police’s Violent Criminal Apprehension Team as he left his apartment in the 2300 block of Long Avenue in St. Paul’s south St. Anthony Park. After obtaining a search warrant, investigators found at least one Federal-brand shotgun cartridge, which matched the slugs recovered at the crime scene, according to prosecutors.

A Hennepin County prosecutor handling the case earlier this week successfully petitioned for a charging extension, writing in a sworn affidavit that there were “already 179 pages of police reports in this investigation, with several more expected to be forthcoming.”

Wood is charged with two counts of first-degree damage to property and a single count of reckless discharge of a firearm. He appeared in court Thursday and was released after posting a $40,000 conditional bond. An omnibus hearing is set for Oct. 11.

One of the conditions: to stay away from the Federal Reserve building.