I uploaded a video I found taken by a taxi driver, who would have been right under the window of where the shooter supposedly was at Mandalay Bay because I found it interesting.

https://www.youtube.com/watch?v=yoDiyWx7BBo

You can clearly hear gunfire coming from two different directions that does not match each other. You can't hear the echo before the actual gunshot, so I just immediately delete the comments that say, "Duh, these are just echoes, derp." I'm actually surprised that YT hasn't deleted the video by now. I typically just upload nerd crap to my YT channel, but on occasion I'll share vids like this and this one has consistently been in the top 3 most-watched video on my channel per month since then.