LITTLE ROCK, Ark. — A 9-year-old girl was responsible for the shooting death of her 7-year-old brother at the family's Arkansas apartment while their parents briefly left to sign paperwork at a nearby leasing office, police said Tuesday.

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

The children's father told officers his daughter has high-functioning autism, but it's not clear whether that played a role in the shooting. 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 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. She also declined to comment on the specifics of the shooting, including whether authorities thought it was an accident.

Prosecutor John Johnson declined to comment specifically about the case because he hasn't seen the reports. He said that Arkansas doesn't have jurisdiction over anyone younger than 10 years old, so charges cannot be filed against a 9-year-old.

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 locked the front door when he and his wife went to sign paperwork, and it was locked when he returned, according to the police report. He told police that after he and his wife returned to the apartment, his daughter said her brother was hurt.

When police officers arrived, 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.

Adrian Dabrney, who lives in an apartment above the family, said he saw the ambulance pull up, but he hadn't heard any gunshots.

"I didn't even know what was going on until the police got here," he said.

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, according to the police report.

Davis declined to comment on whether there were gun locks or other safety measures in place. The police report said officers found two handguns in the case.

Davis said the girl was taken to a medical facility for an evaluation and that she didn't believe the girl was in police custody. A spokeswoman for the state's Department of Human Services declined to comment.

A teary-eyed couple answered the family's door at the apartment complex on Tuesday. They identified themselves as the children's parents and told a reporter they weren't ready to talk.

Earlier this year, the father wrote about his son's birthday in a Facebook post.

"Had the best birthday party with my son...." he wrote. "This kid is 100% me down at that age. Very, very proud of the boy."

The shooting came just hours after the father posted on Facebook about trying to break his lease at the apartment complex, where yellow and purple pansies welcome residents and visitors to the property. The father's recent posts indicate the family was trying to move into a house.

"Well things really went south with Resource Residential, our current property owners," the father posted Monday afternoon. "They called the electric company and told them not to turn off the electricity here, and to cancel the order for the new place."

Resource Residential president, Harland Krichman, expressed sympathy for the boy in a statement Tuesday, but refused to release information about the family.

Earlier this month, the father posted pictures of a house he and his wife were looking at. He shared pictures of the kitchen — "a dream come true" — and one of the backyard.

He wrote in a comment that "from the moment I pulled up in the driveway to look - the immediate feeling of privacy, not sharing a parking lot where people ding up your car, just a much better feeling of wellness immediately came over me."