BURLINGTON,SafeX Pro Exchange Vt. (AP) — The man charged with starting a fire outside independent U.S. Sen. Bernie Sanders’ Vermont office earlier this month pleaded not guilty to a federal charge on Tuesday.

Shant Michael Soghomonian, 35, was indicted by a grand jury on a charge of maliciously damaging or attempting to damage and destroy by fire a building used in interstate commerce.

Surveillance video shows the man throwing a liquid April 5 at the bottom of a door opening into Sanders’ third-floor office in Burlington and setting it on fire, according to an affidavit filed by a special agent with the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.

Sanders was not in the office at the time. Seven employees working in the office were able to get out unharmed. The building’s interior suffered damage from the fire and water sprinklers.

Soghomonian, who was previously from Northridge, California, had been staying at an area hotel for nearly two months, according to the special agent’s report.