Arizona rancher George Alan Kelly already faces a charge of first-degree murder in the shooting death Mexican man. Two charges of aggravated assault were added Tuesday, one day before his preliminary hearing.

Kelly was charged with “using a weapon, a deadly weapon, or dangerous instrument, in an intentional act to inflict injury on [unnamed]”.

Kelly, who is still being held on $1million bond in his own court filing earlier this month, claims he’s innocent. Kelly admits that he fired his rifle at armed drug traffickers in January. He claims that those men are responsible for the death of a Mexican national who was shot to death at Kelly’s borderland property just outside Nogales.

Kelly, 73, was charged with first-degree premeditated killing in the Jan. 30, shooting death of Gabriel Cuen-Butimea (based on his Mexican voter registration card). Brenna Larkin (Kelly’s court-appointed attorney), wrote that the rancher had just finished chores at his Kino Springs ranch and was about to have lunch with his wife. Kelly received a court filing previously obtained from Fox News Digital.

According to the filing, Kelly saw his horse run away scared, and that he was an old horse.

“He finally saw a group moving through the trees surrounding his home. Larkin reported that they were armed with AK47 rifles, were dressed in khakis and camouflaged clothes and carried large backpacks. He didn’t know any of them. He hadn’t given permission for any of them to enter his land.

Kelly called the U.S. Border Patrol ranch liaison because he was “understandably worried and reasonably afraid for his safety, that of his wife, and that of his animals’ safety,” Larkin wrote.

Kelly told his wife to remain inside and to keep her from looking out of windows, then he went on his porch with his rifle.

Larkin wrote that the leader of the armed men’s group saw Kelly and pointed an AK-47 straight at him. “Mr. Kelly fired several shots with his rifle in fear for his safety and life, trying to scare his family, including his wife and animals. Kelly made sure to aim his gun well above the heads of the armed men as he fired. The group ran into the desert around his home. After the group fled, Kelly went to his barn to make sure it was secure and safe.

According to the filing notes, Kelly had another conversation with the Border Patrol ranch liaison. This ended around 2:36 p.m. Kelly claimed that he heard one shot, but the liaison incorrectly reported that Kelly said he couldn’t tell if the men were armed. Larkin wrote that Kelly had reported that he did not hear any shots and that he saw no armed men. Radio dispatched to Border Patrol agents on their way to the property at 2:40 p.m., “correctly reported” that there had been armed men in the area.

Kelly was inspecting his barn when a few Border Patrol and Santa Cruz County Sheriff’s Deputies arrived on the property. Kelly told them that he’d seen several armed men close to his home, according to the filing. Kelly’s wife was also contacted by Larkin, who stated that she saw large backpack-wielding armed men near her house.

According to the filing, Border Patrol agents and sheriff’s deputies searched Kelly’s property “all over”, but did not find anyone. They tried to find the men using various cameras, but failed. The law enforcement officers then left.

Kelly returned to his horse’s pastures as the sun set later in the day. He was still concerned that the horse had been hurt. Kelly noticed that his dogs were focusing on something near a mesquite trees and he approached the area to check on the horse. Larkin wrote that Kelly “observed a corpse lying face down in grass” Kelly called the Border Patrol ranch liaison three times to report the discovery and ask for assistance.

According to Larkin, Kelly assisted law enforcement in finding the body and also cooperated with their investigation. According to Larkin, the investigation revealed that the body belonged to a male “foreign citizen” who didn’t have any firearms nor a backpack. According to the filing, the cause of death was a single gunshot injury. The body appeared fresh.

Larkin wrote that the person had a radio and was wearing tactical boots. This indicated that he might have been involved in illegal activities.

According to the defense attorney, it is not known what type of bullet caused the fatal injury, when it occurred, and where the victim was located before the fatal injuries. Kelly admitted to firing warning shots at smugglers earlier that day, but denied firing any direct shot at anyone, Larkin wrote. He doesn’t believe any of his warning shots could possibly have hit the person or caused death. Kelly shot all of his warning shots on the date of the incident in self-defense.

Kelly and his wife, Kelly, have lived on their property in Nogales, Arizona for over two decades.