Was it a "wise" thing to do? Maybe not, but I'd have to come down heavy on the side of people's "freedom of expression" etc, and I'd also call laws against "brandishing firearms" as too vague to be Constitutional. What is a "brandish"?
Lets remember that even all these latest "mass shootings" put together aren't even half of the on going, less publicized, 'gang related' murders, of which I'm guessing only about 1/2 are guns, and only about 25% are ever even 'discovered' by police for adding to stats.
As far as I know, no one in my HS class was ever "officially" murdered, but two "gang bangers" were "all over town", dealing, and flashing cash and fancy cars one week, then they were simply no where to be found.