What if the "insane" person shoots the real insane person with gun out before he can shoot. Then everyone would just kill the "insane" person.
You should yell out why you are shooting a person or say something like "He pulled a gun out and was aiming!" It's not very smart to pull your gun out or start shooting without people knowing your motive. You do bring up a good point though.
their father owns a gun, bam.
The kid shouldn't possess it still. Also, if you are not smart enough to store your gun and ammo away in a way where kids can't get it, you should't have one.