Now that we know more about the shooter in Las Vegas, one important thing is pretty clear: none of the steps currently proposed by gun-control advocates would have been effective in stopping this tragedy. The shooter appeared perfectly normal to his family and those who knew him. He had no known political agenda, or even interest. He had no criminal record. He had no known history of mental illness. He bought at least one shotgun at a gun store and passed the background check.
He seems to have amassed a sizeable collection of guns (42 at last count), and modified some of them to fire automatically. And apparently even his brother didn't know he had done this. I suppose a national register of all gun purchases might have raised a flag, but even then there are perfectly normal collectors who might own that many guns. He was wealthy, so it would not have been unreasonable for him to have been (or posed as) a collector.
But certainly the usual steps proposed by gun-control advocates, such as universal background checks, would have been ineffective in this case. That doesn't mean they aren't still good ideas, and worth doing. They will stop some shooters. Burt let's be clear - none of the proposed steps would have stopped this shooter. Only eliminating all guns in the civilian population might have been effective, and that is clearly a political non-starter in America, and probably unenforceable in any case.