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.

Federal agents are investigating after a US Border Patrol agent was shot and killed Monday afternoon on the highway in Vermont.

The fuming free speech-advocating president demanded an apology.

David "Chris" Maland, 44, was fatally shot in the line of duty on Tuesday in Coventry, Vermont, according to the Vermont State Police. Maland was an agent with the U.S. Border Patrol Swanton Sector and was conducting a traffic stop at the time.

The FBI is investigating after a U.S. Border Patrol agent and another person were shot and killed Monday afternoon in Coventry, Vermont, just south of the Canadian border, according to federal officials.

The agent was identified as David “Chris” Maland, 44. Maland was a Blue Earth native and a graduate of Fairmont High School.

Agent David “Chris” Maland died in a shooting following a traffic stop, the FBI said. A second person killed in the incident was a German national in the country on a current visa, authorities said.

Governor Phil Scott identified David Maland as the fallen officer, extending his “heartfelt condolences to Agent Maland’s family, friends, and colleagues."