In Germany there are 25 m. guns in private hands (30 per every 100). Firearm regs there include written specs for the lawful storage of firearms & ammunition by licensed owners. The max penalty for illicit possession of firearms is 10 years..
After a school shooting Germany passed a gun law to create an electronic nation-wide weapons registry and unannounced, random inspections in gun-owner homes to ensure requirements for locked gun storage were met.
For many businesses that have licenses, there is a random inspection clause where Health Boards are allowed to inspect your premises.
20/20 once found that parents of children often do not store guns so kids cannot get them. My own did this too. The Newtown mother clearly failed also. Perhaps an inspection would have helped prevent this.