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.

The federal officer killed while on duty near the Canadian border has been identified as a U.S. Air Force veteran who provided security at the Pentagon during the Sept. 11 attacks.

A U.S. Border Patrol agent who was killed in Vermont during a traffic stop near the Canadian border was a military veteran who worked security duty at the Pentagon during the time of the Sept. 11 attacks,