There appears to be just about zero information coming out from the investigation concerning motive. For purposes of this post, let's assume the person who did this was what normals might loosely describe as "nuts." Okay, but why target a gathering of Mormons? If the terrorist considered themself hardline Christian that could be the problem. There are plenty of fundies (probably others as well) occupying various points along the spectrum of professed Christian belief who do not consider Mormons to be Christians. (Catholics often find themselves in this group as well.). To the point of hostility. But "Antifa"? Yeah, right, please go ahead and grab the other one ... it has a bell.

#8
Your observation re the Stalinists and Trotskyites bring to mind Orwell's experience in the Spanish Civil War ... he had to get out of the way of those two factions killing each other off, forget Franco and the fascists.

The LDS outfit, its setup and theology can seem downright odd to nonbelievers. But the same could be said for,all organized religions and their permutations.