Wilson Brandon Scott III, age 13, was charged with felony murder for the shooting death of his sister, according to the Fox 5 Atlanta.

Kyra Scott, 14, was shot at her home during a robbery in Douglas County, Georgia.

Authorities revealed that Kyra was shot Saturday at her home on Vicki Lane, according to The Atlanta Journal-Constitution. She was pronounced dead from her injuries after being rushed to Douglas WellStar Hospital, WJCL reports.

On Wednesday, Douglas County Sheriff Tim Pounds announced during a press conference that they arrested Wilson and 19-year-old Yusef McArthur El.

Authorities detailed what they believe led up to the teen’s tragic death. Wilson was manufacturing and selling semi-machine guns from his home in the metro Atlanta area, FOX 5 reports.

Investigators suggested that McArthur El arrived at the siblings' home as a potential gun buyer, but opted to rob Wilson instead.

"The folks that [Wilson] made the weapon for come to pick it up and a robbery took place, he was going to rob him, take the gun instead of purchase the gun," Pounds told Fox 5. "That's when the shots were fired."

Once the sale exchange went awry, Wilson fired a shot at the assailants, but hit his sister instead.

“A 13-year-old kid, doesn’t weigh but about 80 pounds, was able to make a weapon from start to finish,” Pounds said. “At 13 years old.”

An occupant at the siblings' home called 911 to report the incident as Kyra’s mother rushed to get her daughter help. Police were originally dispatched to the Scotts' home, but rerouted to a nearby gas station, where Krya's lifeless body would be found.

Witnesses say they saw the Scott family pull over at a Marathon in a panic, pleading for assistance.

"They pulled her out and she was lifeless. You could tell that she wasn’t breathing," Jaquan Straughn, a bystander, said. "[Wilson] was crying. He was screaming. He was saying, ‘Don’t die! Don’t die!’ repeatedly."

Pounds said that when authorities arrived on the scene, they were able make out Kyra's gunshot wound.

"We observed there was a young girl in the vehicle who appeared to have been shot," he said.

Pounds expressed his sympathy for the family, as they now have to prepare for the funeral of one child, and possibly lose another behind bars.

"He shot his sister. And it is so sad for this to happen, but a mother losing two kids at one time," the veteran officer said. "And that kind of stuff goes on right under your nose and you never know about it. A 13-year-old kid probably only weighs about 80 pounds, is able to do, make a weapon from start to finish, at 13 years old."

McArthur El has been charged with robbery and felony murder. An unidentified person who accompanied McArthur has not been named. Wilson and McArthur remain behind bars without bail.

Douglas County District Attorney Dalia Racine said that charges will be reviewed after the investigation is concluded.