A 9-year-old boy allegedly accidentally shot and killed his 5-year-old sister with their father’s AR-style rifle, according to police and court documents.

Their father, 33-year-old Irvin Ramos-Jimenez, told police he was out front of his Phoenix home Tuesday night when he heard a loud bang inside, according to the probable cause statement. He said he ran into his son’s room where he found his daughter with a gunshot wound to her torso, the documents said.

Ramos-Jimenez told police he and his girlfriend rushed the little girl to a psychiatric center to meet an ambulance. He said he dropped off his daughter and girlfriend and then drove back home where his children had been left unattended with the gun, the documents said.

Ramos-Jimenez said he stored his weapon “in the top shelf of his son’s bedroom,” adding that “his son must have grabbed the gun,” according to the probable cause statement.

Ramos-Jimenez has been arrested for possession of a weapon by a prohibited person, Phoenix police said.

Ramos-Jimenez was convicted in 2021 of transporting and/or trafficking narcotics, according to court documents. He’s barred from having a firearm and he told police he bought the AR-style rifle “through a private sale for personal protection,” the probable cause document said.

“We ask all gun owners to ensure that all guns are stored in a location, preferably a secured safe, out of reach of all children in the home or who may visit,” Phoenix Police Sgt. Robert Scherer told ABC News via email. “No family should ever have to endure the loss of a child in circumstances like these.”

Guns are the leading cause of death for children in the U.S., according to the Centers for Disease Control and Prevention.

Each year, hundreds of kids in the U.S. access loaded firearms and accidentally shoot themselves or someone else, according to Everytown for Gun Safety. The worst year on record was 2023, when there were more than 400 unintentional shootings by kids, Everytown said.

So far this year, kids have carried out at least 66 unintentional shootings, resulting in at least 30 deaths, according to Everytown.