KRITIQ. Individual examples aren't terribly helpful. I could bounce back the Appalachian School of Law shootings. Three people were killed before the perpetrator was apprehended by two students with personal firearms. The campus police didn't turn up for some minutes afterwards. Nutter on a busy campus with semi-automatic pistol and minutes of shooting? It could have been much worse - more like Virginia Tech god rest their souls.
There's also a county in Vermont where each household is legally obliged to keep a firearm for home-defence. They have one of the lowest crime rates in the US! It's a rural area as well, but crime is low even compared to other rural areas. Maybe they're lucky. Maybe criminals look elsewhere for houses less well defended.
The FBI - who are pretty neutral compared to the rabid anti-gun and pro-gun campaigners - estimate that concealed carry as a deterrent prevents 1m crimes/yr. Clearly it's a complex issue and concealed carry - although foreign to us Brits - has some serious pros and well as it's obvious cons.
My point is that America has 270m firearms - 88 per 100 people. Somewhere in the region of 40-55% of households own firearms. You can't just enact anti-gun legislation because ultimately, if the population rallies and says "no", you can't stick 150million people in prison for not handing in their guns or refusing to register on a new licensing scheme or whatnot. Even 10% (15m) acting out would be an unmanageable group. Stalin tried, but I suspect setting up gulags in the wilder areas of the mid-west will not go down too well with the UN!
And of course they don't have a list. The pistol ban here in 1997 was easy to enforce - the Police had a list of who had guns, how many and what type. If you didn't hand them in by the deadline you got a knock on the door. That can't happen in the US. It's like trying to ban airguns here. The Police don't know if you have an airgun at home or not!
Also of note is that Bill Clinton passed an "assault weapon ban" back in the nineties. It was not renewed when the sunset clause came about because it didn't really work.
I really think the focus should be on mental health. There's no real provision in the US. It's telling that the largest mental health centres there are in PRISONS. The only way to get committed for evaluation is to be charged with a crime - which is a bit like shutting the stable door after the horse has bolted. Gun legislation is easy and media-friendly and wins votes (although in the US it loses some as well), even if it doesn't work very well. Mental health is difficult and expensive, and long term - and Politicians don't tend to care what happens after the end of their term when it's no longer their problem. They're after short term fixes, which is why America has seen lots of bits of gun law here and there (like he popular assault weapon ban, which failed miserably and was not renewed) but nothing effective long-term.