Perhaps, but it doesn't have to be a murderer, if that bothers you. Make it a bank robber, or a rapist who uses a gun. Sooner or later they will be out on the street, and looking for another gun. My point is that the 2d Amendment does not require society to grant them that right.
What reduction in crime do you attribute to the background checks that I am required to pay for prior to buying a firearm?
I would guess very little. It was designed to keep the undesirables from legally purchasing a weapon, not to simply heap additional paperwork on law abiding citizens. The issue still exists of keeping firearms out of the hands of criminals. Only one door has been closed to them. When law abiding citizens can no longer purchase a firearm, then I will be concerned.
On the other hand, nothing in the Constitution would have forbid the government from imposing sufficient punishment to ensure that they don't get back out on the street.
Do you dispute my statement that nearly all people who would pose an unacceptable danger to society if allowed to acquire a firearm would pose an unacceptable danger to society even if forbidden from acquiring one?
I would suggest that while there probably are a few convicted felons for whom a prohibition on firearm ownership would significantly reduce the danger they pose to society, such people are dwarfed in number by those who either would not pose a danger with or without being allowed firearms and by those who would pose a danger with or without firearms.
It's government that would be "granting" the right. Governments don't grant rights, neither does the Constitution, it protects them against government infringement. The rights are assumed to exist. Jefferson said "endowed by the creator", others refer to "natural rights".
Your criteria for concern is that the law-abiding can still purchase a firearm? You would do well in the Kalifornia legislature. Is there any type of gun control that you don't like? I'm out $100 just in the last six months to buy background checks to prove I am not a criminal. I was forced to buy a $25 dollar "Handgun Safety Certificate" because the "good for life" Basic Firearms Safety Certificate that I previously paid $50 for is no longer any good.
I have to buy a trigger lock with every handgun purchase.
Every handgun purchased in Kalifornia must be certified "not unsafe" by the state, costing each manufacturer thousands of dollars for each model handgun they wish to get certified. These costs are simply added to the purchaser's price.
Every handgun and every ugly black rifle has to be registered with the state.
As for actually carrying a firearm for protection? Not a chance in many counties and barely possible in mine.
Even you would guess that these laws do "very little" to affect crime. But it's okay with you? Have no fear. Your turn to see your rights trampled won't be far behind. What is there that can possibly protect them that is stronger than "shall not be infringed"?
Merely concerned? Not even a huff? Reminds me of a quote:
'First they came for the Communists, but I was not a Communist, so I said nothing. Then they came for the Social Democrats, but I was not a Social Democrat, so I did nothing. Then came the trade unionists, but I was not a trade unionist. And then they came for the Jews, but I was not a Jew, so I did little. Then when they came for me, there was no one left to stand up for me.' - Martin Niemöller