Not being pedantic to kneecap you but the language matters. An AR 15 is not fully automatic
I'm not saying this to minimize what happened, or the danger of an ar15, but to clarify that fully automatic weapons are much more rare, and much more dangerous.
I clarified the relevance. The point is the weapons that are being used to do these things are common, and basic. They aren't special weapons of war, which are more regulated, more rare.
You just missed the critical thinking.
Ar 15s are common. Fully automatic assault rifles are far less so.