Shant Soghomonian, 35, who was previously of Northridge, entered the building Friday and went to Sanders’ third-floor office, where security video showed him spraying a liquid on the door and setting it afire, officials said.

The building’s interior suffered some damage from the fire and sprinklers that doused the area with water, but no one was hurt. Sanders, an independent, was not in the office at the time.

Soghomonian was arrested Sunday on suspicion of using fire to damage a building used in interstate commerce, according to a statement from Nikolas Kerest, the U.S. attorney for Vermont.

The motive remained unclear. Soghomonian was detained Sunday and could not be reached for comment. It was not immediately known if he had a lawyer, and an initial court appearance had not been set, officials said.

The crime carries a maximum penalty of 20 years in prison and a fine of up to $250,000.

The case was investigated by police departments in Burlington, Shelburne and Williston; Vermont State Police; the Bureau of Alcohol, Tobacco, Firearms and Explosives; and U.S. Capitol Police, officials said.