Updated

A 9-year-old autistic girl fatally shot her 7-year-old brother at the family's Arkansas apartment while their parents were signing paperwork at a leasing office, police said Tuesday.

The girl initially told authorities two men entered their Little Rock apartment on Monday and shot her brother, but police didn't find any signs of forced entry and nothing in the apartment was missing, according to a Little Rock police report.

The children's father told officers that his daughter has high-functioning autism. He said she "often told stories, and he did not believe that the apartment had been entered by anyone," police wrote in the report.

Little Rock Police Sgt. Cassandra Davis said later conversations with the girl led investigators to believe she was responsible for the shooting. Davis declined to discuss details of the conversations or whether the girl had been tested for residue left behind when a gun is fired.

It was not immediately clear whether the girl could face charges and a prosecutor didn't immediately respond to a phone call seeking comment.

Authorities are not releasing the girl's name because she is a juvenile. The Associated Press is not naming the boy or his parents so as not to identify the girl.

The girl's father told police he and his wife left the apartment briefly to sign some paperwork at the leasing office. He said he locked the front door when he left and that it was locked when he returned. He told police his daughter said her brother was hurt once he and his wife were back.

When police officers arrived at the home, first responders were performing CPR on the boy, who appeared to have been shot in the chest. The boy was rushed to a local hospital and later pronounced dead.

The children's father told police he had firearms in a case in the back bedroom. Authorities found blood marks in that room and closet, along with a large pool in the closet near a silver case.

A man who answered the phone at a number listed for the father Tuesday said he wasn't ready to talk about what happened.