Re: A gun is involved in every single mass shooting.
The firearms are not the problem, it is the culture.
A careful analysis will show that number citizens with firearms, or type of firearms, has no relationship to the number of homicides using firearms.
Furthermore, it has been demonstrated that mass attacks are usually deadlier if they use vehicles than if they use firearms... and the worst domestic origin attack in the US (168 dead, 680+ injured) was done with fertilizer, fuel oil, and a van.
In two recent attacks in Toronto, the disturbed individual with a gun killed 2 people and injured 13, while the disturbed individual with a van killed 10 people and injured 16, some critically, in less time over a greater distance.
The Nice truck attack killed 86 people and injured 468.
Thus, oddly, you want someone to use a gun, as most people are not really that good at it, and because response systems are oriented to dealing with guns, with things like automatic shot detection and location.
You really do not want people to think 'f*ck the gun, I am going to get me an SUV and go on a rampage'.
Finally, gun control does not work in most cases. Countries and places with some of the most stringent gun laws (Mexico, Haiti, Chicago) have very high levels of gun violence, while countries that are armed to the teeth (Switzerland, where the guns do not show up in the statistics gun control lobbyists use because they are not owned by the people keeping those real assault rifles - not the faux uber dangerous 'assault weapons' - in their homes) has a very low rate of firearms homicides.