The Vermont State Police are assisting federal authorities after a shooting involving a Border Patrol agent. They said it happened around 3:15 p.m. Monday on Interstate 91. The FBI is leading the investigation.

Sources tell WCAX News that a third person may have been involved in the shootout that killed a Border Patrol agent during a traffic stop in Vermont.

COVENTRY, Vt. (TNND) — A U.S. Border Patrol agent shot and killed during a traffic stop in northern Vermont Monday was a veteran of the U.S. Air Force who worked security at the Pentagon during the Sept. 11 attacks, according to his family and officials.