I don't understand. Shotguns not only have a lower capacity, but they also have lower range and longer reload times. Sounds like they aren't going to be as effective in a massacre as an AR 15.
No matter what firearm you use, at close range, you will kill. Assault Rifles aren't fucking necessary.
Shotguns don't have a lower capacity And do not have a longer reload time. Shotguns have clips just like rifles. Even the ones that don't have speed loaders. The range doesn't matter. Shootings take place at around 15 yards. 95% of police engagements take place at 7 yards or less. This is why police carry pistols and shotguns.
Also, Assault rifle is the broadest term on the planet. Any rifle can be classified as an assault rifle. Keep in mind the past two shootings have happened using illegally obtained firearms.
I actually do use an AR. I use it to keep up my accuracy. Not only that, I use it to hunt predators. It is THE perfect weapon for hunting Coyote and Fox. Against defenseless people, just about any firearms with enough ammunition is going to do unspeakable damage.