There is always going to be this problem in USA ,Due to the facts that if you do,nt have a criminal record and appear to be a good member of public you can get a gun license easily. Depending on state you in you may be able to get hold of semi auto or full auto rifles. But here's the clincher the government policy on mental health in USA is somewhat lacking! Compared to what it used to be say 40-50 years ago, ie there would be a very large amount of American public in asylums getti ng treatment for mental health problems if they still had there old policys, probably down to cost cutting! so if you put it all together you,ve got well armed loons waiting to kick off. But with all this info out there and freely available how come most people in U S cannot see this? the U S Gov is not blind, so what is the bigger picture? I personally would not like to guess for fear of being called a loon! LOL But i guess the powers that be in the U S are gonna try to pin blame on innocent, peaceful parties rather than take it on the chin and admit that they brought it on themselves.