Register guns annually
We need a law that not only requires that every gun be registered, but that every gun be registered every year, and in that annual registration, gun owners certify that (1) they still have possession of it and (2) that it is secured under lock and key. The gun owner should also be required to take a blood test for drugs and to demonstrate knowledge of gun safety (probably by taking a class).
If you own a gun, you need to keep it out of reach of everyone else. If you don't, you're breaking the law, and if your unsecured gun is used in a crime or youth accident, you must do some jail time.
Yes, owning a gun is a right. But every right has responsibilities and consequences for ignoring them.
Heck, if we annually register cars and make sure they're safe and license their owners all in the name of public safety we should do the same for guns and their owners.