From the article:
The deputy approached the car and saw the 15-year-old boy in the front passenger seat, with a gunshot wound to his lower back. The other passenger remaining inside the car was the victim's brother, 28-year-old Saul Granados, who also was sitting in the front seat.
The victim was taken to a Modesto hospital and treated.
Deputies found a sawed-off shotgun inside the car.
After further investigation, deputies determined one of the car's occupants in the back seat shot the victim by accident. Deputies are still determining whether the victim was shot with the shotgun or another weapon.
Both the victim and his brother are validated gang members, according to deputies.