Moron! First of all, the arguments for such a registry are far from common-sense, as they can be defeated and/or gamed easily, to wit:
1) Use a revolver and leave no brass.
2) Use a sawed-off shotgun and leave no brass (and also have a far more lethal weapon).
3) Grind down the firing pin.
4) Replace the firing pin.
5) Pick up brass from somewhere else and drop it at the crime scene - this would at a minimum make for much more work for the police, even if they "got their man." Worse yet would be to implicate others. The crown jewel would be to use the same model of handgun used by police in the local jurisdiction, and get your throw-down brass from a range that the police practice at. Oh, would there be fun and games then!
As anyone with any sense knows, criminals will simply not obey this law. It is a simple attack on law-abiding gun owners, in this case by making it more expensive to buy guns (you don't think that the manufacturers will do the machining and keep a database for free, do you?). Plus, it further ingrains the concept of the government dictating what we can and can't buy.
6) Aren’t there small accessories that resemble a mesh bag that attaches to a semi-auto pistol’s slide to catch the brass as it ejects?
7} With $600 invested in a very simple mechinists lathe, vertually anyone could crank out firing pins in a garage for a few dollars a piece in material.