The pace of mass shooting picked up substantially starting around 1975, and it's accelerated over the last 20 years or so.
I wonder what changed? But that detracts from the political points that have and must be made, so . . . root cause analysis is not allowed!
Colt’s patent on the AR-15 ended in 1977 & production of similar style guns across multiple manufactures picked up.
That's laying the burden entirely on the weapon.
I saw an article awhile back about how you could buy an M30 Carbine WWII Army Surplus out of a mail order catalog for $30 in the 1950's. Our society and culture has changed. Back then we had a lot more people in our country who understood what it meant to point a loaded gun at a person and pull a trigger. We don't have that anymore, and thus our society must adapt by banning certain types of guns, accessories and modifications and changing laws to slow the immediacy and ease of obtaining the subset of firearms that are legal to buy and own.
We are a society that has a super high tech military that advertises that they're a super high tech military and that has glamorized the "Going Tactical" mindset. Our media has helped propagate that as well. Games like call of duty allow children and adolescents to pick out their assault weapons and go kill computer generated images and when they get killed they just keep respawning - desensitization. Much of that is done in households that don't have any guns, so there's no real world experience with guns, there's no gun safety taught and there's no talks about what it means to point a loaded gun at another human being. We have other video games that make look cool to have guns and to go out and kill people, and we have the cool guys don't look at explosions or stay and count the dead in our movies.
But those are just symptoms and components of the overall problem.