The shooting along the border between Mexico and Arizona is being investigated by the FBI and the Cochise County Sheriff's Department. Agent Nicholas Ivie was killed and another agent injured.
Three sources told The Arizona Republic the shootout may have involved two groups of agents who both believed they were under attack. The agents were responding to a report of an alarm from a sensor.
Homeland Security Secretary Janet Napolitano traveled to Arizona for a private meeting with Ivie's family. She was also scheduled to visit the Border Patrol station in Naco, Ariz.
Ivie, a native of Provo, Utah, is survived by his wife and their two young children. His funeral is scheduled Monday at the Church of Jesus Christ of Latter-day Saints in Sierra Vista, Ariz.