Jamison Childress, a 20-year-old man, has been identified as the individual who was fatally shot by a U.S. Customs and Border Protection agent on Thursday afternoon near the B.C.-Washington border.

A statement from the border agency said agents responded when a sensor was activated near the Sumas, Wash., border crossing at around 2:30 p.m. PT.

Chief patrol agent Dan Harris Jr. said in the statement that Childress failed to follow verbal requests from border agents and displayed "erratic and threatening behaviour" before spraying an agent with an unidentified chemical.

The man was later identified as Jamison Childress. (Google)

Harris Jr. said the agent opened fire on Childress, and he died of a single gunshot wound to the head. The agent was later transported for medical treatment.

Whatcom County sheriff Bill Elfo said investigators found a hatchet inside a backpack that Childress was carrying.

Elfo told a news conference Friday morning that Childress was wanted for murder in another jurisdiction, but he did not say which.

B.C. court records show a man with the name Jamison Childress was charged with mischief, theft and assault in Fraser Lake and Prince George between 2013 and 2014.

Ongoing investigation

Canada Border Services Agency spokeswoman Jennifer Bourque says the agency was not involved in the situation, and Canada's port of entry was not affected.

Several federal and local U.S. agencies are now investigating.

The Department of Homeland Security Inspector General and U.S. Customs and Border Protection Office of Internal Affairs are leading the probe.

Harris Jr. says the agents involved in and present during the shooting are currently on administrative leave, as is standard policy. The agents had between 10 and 19 years of experience with the agency.

"A shooting is a very traumatic event for any law enforcement officer," he said.

"Taking another human's life is the last thing that we want to do. Our agents are dealing with the emotional aftermath of such an event."

Uncertainty about murder charge

Vanderhoof, B.C., lawyer Michael Reed says he has represented a B.C. man with the name of Jamison Childress several times but never on a murder charge.

"Any time I talked to him he presented as a polite young man. He was always very calm and well-spoken," said Reed.

He said he was in "disbelief" about the shooting.

Another lawyer, Fred Fatt, confirmed a client of his named Jamison Childress was set to appear in a Prince George court Friday morning, but he did not appear.

Prince George RCMP Cpl. Craig Douglass could not confirm that the Childress with a criminal record in B.C. was the same man who was killed in the U.S. He said the Childress charged in B.C. had not been accused of murder.