The job of a U.S. Border Patrol agent is to defend the nation’s borders not to fatally shoot a fellow citizen because of a personal spat.

According to a report from The Associated Press, 40-year-old John Demery, an off-duty U.S. Border Patrol agent in the San Diego region, allegedly shot and killed 27-year-old Adam Thomas in Hemet, California, on Saturday.

A statement from the Riverside County Sheriff’s Department alleges that Demery confronted Thomas at a home in Hemet. The confrontation led to an argument between the suspect and victim that eventually resulted in the victim being shot several times. Thomas was transported to a hospital, but later died due to his injuries.

“We are sad and shocked,” National Border Patrol Council spokesman Gabe Pacheco said in a statement obtained by  Reuters. “We’re waiting for more information from the investigation.”

Reuters adds that Demery has been placed on suspension and administrative leave pending the release of further information in the ongoing investigation into the murder.