I suppose that we should be grateful that this latest Leon Czolgosz-wannabe wasn’t as well prepared as he should have been. Clearly, he went straight to the “Suggested Assassin’s Weapons” tab at Amazon or something — that is to say, he got some things quite right, and a lot of other things very wrong. Consider this series of pics of his “arsenal” which he hoped to use at the Hilton D.C.:

Okay, let’s look at this “arsenal”.
- Pump shotgun: Yes of course. If you’re going for “maximum damage in a confined area”, there are few better choices. One might argue that a semi-auto would be a better choice, but potato-potahto.
- Colt 1911 model: Also a solid choice for a handgun, although he may have been better off with one of those guns which carry a 500-round magazine, e.g. a Glock. Still, the chances of him getting to actually use a handgun (any handgun) during a mass shooting are going to be minimal, unless the 1911 is backup for when you run out of 12ga ammo. But:
- Knives (4, assassin for the use of): Four knives? For a gunfight? Okay, by all means carry a knife as part of your EDC accoutrements (I do), but let’s be honest about this: in his proposed scenario, a knife — any knife, let alone four — will be about as useful as a golf club, maybe less so. And: two throwing knives? Useless; toss them for a couple spare magazines (which you are going to need if shooting a 1911; ask me how I know this.) Also, a Ka-Bar is too unwieldy; that boot knife (which I carry when wearing cowboy boots) would be the only decent option here.
I still think that the Secret Service missed a trick by not shooting the asshole dead on the spot, but that’s just me. Given how inept the SS have been with their handguns in the past, however, subduing the scrote might have been the better option; at least there was no collateral damage.