A 9-year-old boy fatally shot his 5-year-old sister Tuesday night, and their father was arrested for illegally possessing the weapon used in the killing, police said.

On Tuesday night, detectives were called to a home in the 500 block of West Wier Avenue in South Phoenix to investigate a shooting. Just after 9 p.m. June 3, officers were called to a behavioral hospital in the 1200 block of South 7th Avenue for a stabbing, but they learned the girl had been shot in her Wier Avenue home and was driven to the hospital by family members, according to a Phoenix Police Department release.

The 5-year-old was taken by ambulance to a local trauma center where she was pronounced dead.  

Additional officers went to the home, and investigators arrived. They learned the girl’s brother had shot her accidentally, police said.

During an investigation, detectives learned the rifle used in the shooting belonged to 33-year-old Irvin Ramos-Jimenez, the children’s father, who was later arrested and booked into jail for possession of a weapon by a prohibited person, according to the release.

The investigation is continuing.