KANSAS CITY, Mo. (AP) — A student accused of taking weapons and more than 100 rounds of ammunition to his northwest Missouri school has been charged with two counts of possessing illegal firearms.

Federal prosecutors in Kansas City charged 19-year-old Michael Knoth on Wednesday. Knoth had previously been charged with unlawful use of a weapon and making terrorist threats with reckless disregard.

He has pleaded not guilty to those charges.

Knoth was arrested at Tarkio High School on Feb. 11. Prosecutors say he was wearing body armor and military-school clothing when he was stopped. No shots were fired and no one was injured.

Court documents say a search of Knoth’s home turned up firearms that “displayed the traits of a machine gun.”