Perhaps along with a new bureaucracy to go house to house and check on the storage conditions? The Swiss did something like this when they required men/reservists to store their battle rifles at home...but not really. Absolutely unworkable on a national level. Oh, and what states really have an idea of what guns are where?
they are not going to check
but if the kid does something illegal they can go after the parents
scare everybody into locking up their guns making them ineffective for self defense
“Oh, and what states really have an idea of what guns are where?”
With universal gun registration, Hawaii thinks it does.
The police do not have the resources to enforce that law, even for the fools that obey it. Much less check for gun locks.