So, I try not to be prone to conspiracy theories, but some media organizations forced some documents to be released from the case today and I'm sort of on board with the idea that there might still be a shooter on the loose.
Here's a pretty decent CNN article about the documents that were released
In summary, Paddock was using two email accounts associated with the apartment complex he owned to communicate with each other. He is believed to have owned both accounts, but the communication between them makes more sense if one account was shared by potential customers.
Account 1 (centralpark1) emailed Account 2 (centralpark4804) the following: "Try an ar before u buy. We have huge selection. Located in the las vegas area"
Account 2 responded: "We have a wide variety of optics and ammunition to try"
Account 1 responded: "For a thrill try out bumpfire ar's with 100 round magazine"
It seems plausible to me that someone set up a deal with Paddock at the hotel, killed Paddock, used the guns and then managed to escape. That theory begs the question of what the security guard who was shot saw, as presumably no one could have escaped that room without him having seen them go. Did he ever end up giving a public account of what happened? I know it was scheduled to happen and then he kind of disappeared, but that was months ago and I never paid attention to any follow up.