A U.S. Border Patrol agent killed during a traffic stop near the Canadian border worked security duty at the Pentagon during the time of the Sept. 11 attacks.

David Maland, 44, was a military veteran who worked security duty at the Pentagon during the Sept. 11 attacks, his family said.

David “Chris” Maland, the Border Patrol agent killed Monday, was shot while conducting a traffic stop in a Vermont town near the Canadian border, according to the FBI’s latest update on the case.