A Pennsylvania man charged with beheading his father and calling for a violent overthrow of the federal government may have also been planning an attack on federal buildings, officials said Thursday.

Justin Mohn had a flash drive containing several photos of federal buildings and instructions that appear to show how to make explosive devices when he was arrested Jan. 30 on the grounds of the National Guard Training Center in Central Pennsylvania, according to the Bucks County District Attorney's Office.

The office on Thursday filed additional charges against the 32-year-old on Thursday including three counts of terrorism, possession of an instrument of crime, robbery, theft, defiant trespassing and other related offenses. 

Mohn was already charged with first-degree murder, abuse of a corpse, and possession of an instrument of crime. He remains in Bucks County Jail without bail.

On Jan. 30, Mohn's mother, Denice, called police after she discovered the decapitated body of her husband, Michael Mohn, in the first-floor bathroom of their home in Levittown, a suburban outpost about 25 miles northeast of downtown Philadelphia.

When officers arrived, they found the father's head wrapped in plastic, inside a large pot, according to a probable cause affidavit. Investigators located a machete and a large kitchen knife in the bathtub. According to court records, Justin Mohn posted a 14-minute video on YouTube in which he held his father's head and urged viewers to take action against federal employees.

Justin Mohn allegedly fled to the National Guard Training Center in Lebanon County, Pennsylvania, where he climbed a barbed wire fence before being apprehended.

He told the sergeant who took him into custody that the barbed wire around the property was “not sharp enough to keep him out,” according to a probable cause affidavit.

Mohn told authorities that he went to the military base in an effort to mobilize the Pennsylvania National Guard to raise arms against the federal government and to speak with Gov. Josh Shapiro to to get him to “join forces” with him.

A search found a loaded 9 mm handgun Mohn purchased the day before in his jacket pocket, the affidavit said. Authorities say he did not have a valid license to carry a concealed firearm or valid sportsman’s permit.   

Authorities obtained a search warrant Feb. 6 for the USB drive that authorities found on Mohn and located a folder titled “us army improved munitions handbook” that included several pictures of federal buildings along with instructions appearing to show the steps needed to make explosive devices, the affidavit said. 

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