We already have background checks for weapons purchased from a dealer at a shop or gun show. We have had killers who did pass the background check and still used those weapons for mass murders.
Your right it’s not a full proof system, some get through. Would you do away with the background check system we have or do you think it is doing some good?
Half and half on that.
Are they stopping people not legally allowed to buy a gun to buy one at a dealer? Yes they are. Are they stopping people who are not legally allowed to buy a gun to buy one elsewhere? No it doesn't.
Go to your pharmacist and ask for a bottle of Oxycontin, and he refuses to sell it to you without a prescription. Go to the street and it's ready available.
The question is, did you solve anything by forcing the addict to buy from the street instead of the drug store? No you didn't. Did you stop all law abiding citizens? Yes you did.
So let's say a evil or twisted person wants to commit a mass murder. Do you really think that the inability to buy a firearm at a dealer will make him say "Oh well, I guess I can't do it now!"
London is trying to institute a law that stops people from carrying knives outside of their home. Why? Because knife killings surpassed murders in New York City even with the available guns.
It's the old cliche. Guns don't kill people, people kill people. If you take a nice middle-class suburb, and create a law that all households must have at least one firearm, you won't change the crime statics one bit. Create a law in lower income neighborhoods that nobody is allowed to own a firearm, the same thing. You won't change the crime statistics one bit.