I read Paddock had far more weapons than he could have hoped to use himself. I read they found Antifa (which I will henceforth refer to as Fascist) literature in his room. I read there is a police account and a different account as to when he checked in. I read he apparently had a guest https://www.infowars.com/receipt-shows-paddock-had-another-guest-in-his-room-before-shooting/
Put all this together, along with low simmering unresolved emotional trauma, and relentless left wing propaganda calling for violent resistance to the expressed will of the American people, and a relatively high IQ, and what I get is this guy conceiving an excellent scheme for the mass murder of likely Trimp supporters. I see him inviting many people to join him, at least one of whom actually visited his room. I see him sharing Fascist literature with him or her, and showing off his gun collections, and all the windows looking down on the spot where the country show was going to be.
I see cops reaching this conclusion early and going on a hunt for people who knew of his plans to due to direct invitation, and who chose not to join him on his suicide mission, which was the part they objected to, not the murder part, for which they applauded him, as some leftists have had the audacity and cruelty to do publicly.
So a hunt begins, with little information to go on. Perhaps he effectively wiped all his devices. Perhaps he left few clues. Perhaps there were no cameras in his hall, leaving them to guess who, among tens of thousands of visitors–many of whom were not guests–might have come to see him. This would be a MASSIVE undertaking and until they can get a confession–unlikely even if they find someone who knew–they have nothing.
His girlfriend has a practiced alibi and nobody can prove she knew anything g.
So in the end, after tens of thousands of hours of work, they have to propose a possibly radicalized lone shooter as their best guess, not wanting the public to know their real best guess is that up to dozens of people may have gotten away with complicity to mass murder.