Aunt charged with child endangerment after 10-year-old boy playing with gun shoots dead 12-year-old brother

Police arrested Aja Johnson, 36, after she confirmed the gun used in Tuesday’s shooting belonged to her

The aunt of a 10-year-old boy who shot and killed his 12-year-old brother while they were playing with a gun at their St Louis home has been charged with child endangerment.

Police arrested Aja Johnson, 36, after she confirmed the gun used in Tuesday’s shooting belonged to her.

According to a probable cause statement, three children were unattended while playing in a bedroom where a loaded gun was lying on a bed.

Ms Johnson’s 10-year-old nephew thought the weapon was unloaded when he picked it up, pointed it at his brother and fired, the affidavit states.

Ms Johnson allegedly told investigators she had left the gun in the bedroom and that “she was to blame for (the victim’s) death”.

She is now facing a charge of second-degree endangering the welfare of a child and is being held without bail.

The affidavit noted that the children had played with the gun during previous visits to the home in the Walnut Park West neighbourhood of north St Louis.

Aja Johnson, 36, was charged with child endangerment after her gun was used in a fatal accidental shooting by her nephew (St Louis Metropolitan Police Department)

Police identified the 12-year-old victim as LaFrance Johnson, a sixth grader in the Rockwood School District, according to KSDK.

Earlier reports said the boys were playing with the gun while their parent was in the house getting a haircut.

The tragedy came as St Louis police raised alarm about a recent uptick in accidental shooting deaths and injuries among children.

LaFrance Johnson, 12, was shot and killed accidentally by his 10-year-old brother in St Louis (Family handout via KSDK)

Days earlier, another 12-year-old and a 14-year-old were shot and killed while attending a birthday party at a rented apartment in the city.

The 12-year-old girl was reportedly streaming on Instagram Live while she was playing with a gun at around 2am. She shot and killed her cousin accidentally, then reached for the gun and accidentally shot herself in the head, according to the family

Last month, another 12-year-old girl was wounded during an accidental, self-inflicted shooting.

The shootings have prompted St Louis Metropolitan Police Major Ryan Cousins to urge residents to install gun locks on their weapons.

“This is like the third incident in a week we’ve had so far. Prior to that, we have sent out information to the alderpersons about receiving gun locks,” Mr Cousins said. "As an agency, we will come out and teach everyone how to use them. We do understand people are going to own guns; however, to protect these children, we want to ensure these guns are secured safely.”

The city began giving away free gun locks in February to help reduce gun deaths from accidents and suicides, which account for the majority of firearm deaths. Approximately 4,500 gun locks will be distributed, with priority placed on homes where gun accidents have already occurred and homes in which children are living in the same home as a registered gun owner.

“No matter how this turns out, I want to remind everyone that the St. Louis Fire department, all 30 stations, have gun locks," St Louis Director of Public Safety Dan Isom said. "We encourage people to go to those stations to get gun locks to secure weapons so we can keep young people safe.”