JACKMAN — Two border patrol agents who were involved in a fatal shootout in a home where a domestic disturbance had occurred went inside thinking that a woman was in danger, when she had already left the home, according to the Attorney General’s Office.

The agents, Jamie Tierney and Chris Demanski, returned fire with a rifle and a handgun after the home’s occupant, Charles Robinson, 75, fired a shotgun blast that injured Tierney on June 23, investigators said. Robinson was hit once in the chest and died at the scene.

The Attorney General’s Office said Monday that Tierney fired the fatal shot and that both agents met the legal requirement for using deadly force.

The incident started when Robinson’s companion called Jackman Regional Health Center to report that he had been drinking and had fallen down, hurting himself. Enraged, Robinson threatened to kill her and then yanked the receiver from the base of the telephone, investigators found.

Hospital workers notified law enforcement officials, who dispatched border patrol agents.

Robinson’s companion slipped away from the house after the phone call and went to the hospital, said Martha Demeritt, spokeswoman for Attorney General William Schneider.

Thinking that the woman could be injured or in danger, the agents banged on the screen door, announced their presence and entered a wide-open front door. They were confronted by Robinson, who fired a single shot, investigators said. Some of the pellets hit Tierney.

After exchanging gunfire, the two agents backed away to await additional agents, investigators said.

Robinson, who was later found dead in the home, died from a single bullet that went through his arm and into his chest, according to the medical examiner. His blood-alcohol content was 0.155 percent, nearly twice the legal limit for driving.

Schneider found that the agents believed they were in imminent danger and that deadly force was necessary to counter the threat, meaning the legal threshold was met to preclude criminal prosecution.

The review does not include an analysis of potential civil liability or whether administrative employment action is warranted.