A U.S. Coast Guard lieutenant accused of using his government computer to plot a domestic terrorist attack pleaded not guilty to drug and weapons charges during his latest court appearance Monday.

Christopher P. Hasson, 49, appeared in U.S. District Court in Maryland almost two weeks after he was indicted on additional weapons charges related to what the government says were silencers found among a stockpile of weapons seized from his basement apartment.

Hasson was arrested Feb. 15 on drug and gun charges after a computer program the Coast Guard uses flagged suspicious activity tied to his work devices, federal law enforcement officials said. Hasson has not been charged on any terrorism-related counts, but prosecutors allege that was planning an attack on politicians and media personalities to advance his white-nationalist views.

Hasson created a spreadsheet of targets and “traitors,” studied the manifestos of mass attackers and conducted Internet searches of security protocols for liberal elected officials and of where members of Congress congregate, the government said.

“The defendant intends to murder innocent civilians on a scale rarely seen in this country,” the government said in court documents, adding that investigators believe Hasson called for “focused violence” to “establish a white homeland.”

At a previous hearing, a federal public defender for Hasson, Julie Stelzig, argued that there was no indication he planned to carry out an attack and that it is not a crime to have negative thoughts.

Hasson did not speak during Monday’s hearing other than to give his age, say he completed two years of college and answer mostly yes-or-no questions from the judge.

Assistant U.S. Attorney Thomas Windom said a trial for Hasson could take about five days.

Elizabeth Oyer, a federal public defender for Hasson, represented him on Monday and declined to comment after the hearing.

Separately Monday, Magistrate Judge Charles B. Day granted the government’s motion to keep Hasson detained during trial. Day had initially ordered Hasson held for at least 14 days at a Feb. 21 detention hearing, during which prosecutors and Hasson’s attorney argued over whether it was appropriate to keep him jailed over drug and weapons charges but no terrorism-related counts. Day gave the two-week window for the government to bring forward new charges before Hasson’s attorneys could appeal his bail status. The government added two new weapons charges by way of indictment less than a week later.

Hasson, who lived in a Silver Spring apartment, has served in the Coast Guard for more than two decades. His secret security clearance has been suspended, Coast Guard officials said. Hasson also previously served in the Marine Corps and the Army National Guard.

Hasson has been charged with possession of firearms and ammunition by an unlawful user of a controlled substance, unlawful possession of tramadol, and two counts of unlawful possession of silencers. Prosecutors said the silencers did not have serial numbers and had not been registered as required by law.

Hasson faces up to 31 years in prison.