TUCSON, Ariz. -- The FBI has preliminarily ruled that the shooting death of U.S. Border Patrol Agent Nick Ivie was a result of friendly fire.
The FBI said late Friday that it believes Ivie’s killing and the injuries to the second agent were the result of an accidental shooting that only involved the agents, not suspects.
The Cochise County Sheriff's Office, which is assisting the FBI in the probe, said federal investigators used ballistic testing to determine the shootings likely were the result of so-called friendly fire among the agents.
Neither the FBI nor the Border Patrol would explain which agent shot first or whether all three agents had fired in confusion.
Early Tuesday morning, Ivie and two other agents were investigating a tripped ground sensor near Naco, Ariz. Ivie was killed at the scene. One of the other agents was shot in the ankle and buttocks, but was released from the hospital after surgery. A third agent was not injured.
Homeland Security Secretary Janet Napolitano traveled to Arizona on Friday to express her condolences to Ivie's family and meet with authorities. Regional Border Patrol Commander Jeff Self said the Ivie would not be forgotten.
“That he will be remembered by all of us who served alongside him for his character, his kindness and his loyalty,” Self said.
The FBI would not say what will become of the people arrested in Mexico in connection with this case.
Arizona Gov. Jan Brewer stood by the criticism she leveled earlier this week in response to the shootings in which she said a political stalemate and the federal government's failures have left the border unsecured and Border Patrol agents in harm's way. She plans to attend Ivie's funeral Monday in Sierra Vista, Ariz.
The Associated Press contributed to this report.