NACO, Ariz. -- The FBI said a preliminary investigation has found that the death of U.S. Border Patrol Agent Nicholas J. Ivie was likely the result of friendly fire.
The FBI stressed that the investigation is continuing.
Ivie and two other agents were responding to a tripped sensor in Naco near the Arizona-Mexico border Tuesday when the shooting occurred.
Ivie was fatally shot. A second agent was shot in the ankle and buttocks. He was released from a Tucson hospital after surgery. The third agent was not injured.
FBI Special Agent in Charge James L. Turgal Jr. said Friday that there are strong preliminary indications that Ivie's death and the second agent's injury were the result of an accidental shooting incident involving only the agents.
The last Border Patrol agent fatally shot on duty was Brian Terry, who died in a shootout with bandits near the border in December 2010. That shooting was later linked to the failed Fast and Furious operation.