Right, because if some crazy asshole shoots people randomly it's a mass shooting but if he happens to be muslim it's terrorism. Sorry, keep forgetting about that memo.
That it's possible for a determined group to acquire guns and attack people is one thing. It being possible for a single mentally unstable person to do so is quite another.
What about Columbine (multiple shooters, conspired in advance to commit the attack), terrorism, mass shootings?