From the article:
The Murray County Sheriff's Office said the 12-year-old was riding in the front passenger seat when he was accidentally shot by a younger child sitting behind him.
It happened around 10 in the morning. The boy was taken to Mercy Hospital in Ardmore in stable condition. Investigators said the child with the gun did not know it was loaded.Reports do not indicate the type of weapon nor how the child in the back got the gun.
Every gun in the hands of a child must first pass through the hands of an adult.