“Did he buy them over time legally? Highly unlikely.”
There was already reporting yesterday from 2 different gun stores in the LV area that confirmed sales to the guy that were processed through NICS in the required fashion. Plenty of reporting on him being well-off so he could pretty much whatever he wanted, whenever he wanted.
Take off the tinfoil beanie and try to keep up. Delving into your favorite conspiracy or UFO theory is not a good strategy for beating back the ignorant gun-banners at the gates.