William Dong, 23, is charged with unlawful transport into Connecticut of a semi-automatic Bushmaster rifle. An agent with the Bureau of Alcohol, Tobacco, Firearms and Explosives said in an affidavit that Dong told him that he bought the rifle in Pennsylvania in September.
Dong has been in state custody since his arrest on Dec. 3, when he was a student at the school. He appeared in federal court in New Haven on Tuesday and prosecutors say he agreed to a federal detention order. It wasn't immediately clear Tuesday if he was still enrolled in UNH.
If Dong is convicted, the federal charge carries a maximum penalty of five years in prison and a $250,000 fine.
His attorney, Fred Paoletti, said last month that he expected Dong to plead not guilty to state weapons charges. Paoletti could not immediately be reached for comment on the federal charge.
Authorities say Dong was arrested carrying two loaded handguns on campus and had the Bushmaster and bullets in his car parked nearby. The campus was locked down for more than four hours as police arrested Dong and searched the school grounds.
Police say they found 2,700 rounds of ammunition and newspaper clippings about the Colorado theater shooting at Dong's home. Police have said they weren't sure why Dong brought the guns to campus.
