Mandatory requirements for firearm storage and firearm security measures for civilians.
Owners of firearms must prove that their firearms can be stored in a safe, or lockbox.. etc. to prevent unauthorized use or theft of a firearm.
Additionally, the firearm should be sold with a trigger lock, mechanical block, etc.... so that only the authorized user can function the weapon.
Firearm storage/security should be a factor in the sales of a firearm. Verification that the buyer has a safe via serial number, or required trigger lock should be part of the sale.