I heard about the shooting on TV around two hours after it started at 2210 hrs Oct 1. By three hours after start there were already eye-witness videos posted on Twitter. I listened to several of them and posted this at 1 AM Oct 2:
Unless I’m hearing echo, I guess at least two shooters, fully automatic #lasvegasshooting
— Steve Parker, M.D. (@steveparkermd) October 2, 2017
Advanced Mediterranean Diet 
Eyewitness accounts, especially early in a chaotic situation, have been studied and shown to be hugely unreliable. We still have people who think a Middle Eastern man was at fault for the OKC bombing because some lone witness was willing to tell that to a reporter for 15 minutes of fame. Who cares if the bomber himself freely admitted to doing it?
Thanks for contributing,John!