Why would you have any buyer unknown to you come to your home, to look at a weapon?
Even without mandatory background checks, I think this is a particularly bad idea.
because I have done so.
because he was a service member.
because it is no one's business.
it's a free country (I still have hope).
You have foibles about it, but it isn't up to me to play "Minority Report, Future Crimes Prevention" and frankly I find the idea that you can prevent a crime is simply unrealistic.
Don't think so, name a crime you can prevent with a law. I am only asking for one.
Many people don't think this way. Some people do think this way. Some people look to laws and the government for guarantees in a world that doesn't do guarantees. Some people have this unrealistic need for security and will insist on the craziest things to "feel" secure. Some people now play a major role in all politics.
Feel free to substitute whoever and whatever you wish for Some people.