A 14-year old Traverse City, Michigan boy was found by his father to have stolen a handgun from a vehicle, intending to deliver it to another 14-year old boy and a 16-year old boy.
The gun owner did not realize the gun was missing until police told him. It was not reported why the gun owner had left the gun in an unlocked and unoccupied car, or why he didn't realize it was missing.
From an article:
Every gun in the hands of a child must first pass through the hands of an adult.