So the writer is full of crap. The boy didn't turn in a found weapon. He flipped when the discovery of his crime was imminent, hoping to get a light sentence.
I should've been more suspicious: Since when is a "pellet" gun a "toy" gun? It's not the same as a rifle or handgun, but it's no toy. In my head, I thought of something akin to those plastic-disk-shooting guns, but I know better. A pellet gun is a gun that can be used to inflict significant injuries. If I were the principle, I might check the rule books and see if the "zero tolerance" policy truly applies to non-explosive "guns," but I would shed no tears if I had to suspend the kid for a long time.