It always comes down to laws being the problem.
The solution is simple: a law banning all laws.
Ask Mexico how well their rather strict gun laws have been at preventing mass shooting along the border.
If you didn't have a permit when the law changed in 1982, you cannot possess a handgun in the city (even in your own home). I moved there just before the ban and would have had to take my guns back home in order to be legal.
Let's just ban people from living in Colorado that seems as though that would have solved a few mass shooting issues.
I'm a little late for the party as usual, but allow me to point out that certain types of semi auto firearms are STILL legal in the UK.
The types of weapons I'm referring to are rimfire semi auto rifles, semi auto shotguns that hold over 3 shells or have detachable magazines, and are available for legal purchase on a Firearms Certificate (FAC).
Also, no calibre limit or "sporting exception" system as in the gun savvy U S of A. In case you missed it, that means that a 76mm (3in) AT gun is classed as a rifle. But then again, you wouldn't know what the AT designation stands for, would you?
The simple truth stringent gun control doesn't stop mass killings
Osaka school massacre -with a knife- 8 Children dead 13 Children wounded 2 teachers wounded.
Akihabara massacre - a man hit a crowd with a truck, killing three people and injuring two; he then stabbed at least 12 people using a dagger killing four people and injuring eight.
oh **** it here is a list of rampage killers via wiki
Not sure the amount done with guns vs other things but it seem to me that if you want to kill a bunch of people you will find a way.