He not only showed it around, but plugged it in during English class where it made beeping noises. Do you expect the English teacher should need to "verify" a box of wires and circuits? Who would she verify it with if the kid plays aloof when asked of its purpose?
Just because "authorities apprehend 14yo Muslim kid for home-made clock" doesn't mean you need to start making accusations of bigotry, ignorance and cowardice.