Some are suggesting on social media that he might have treated this as a “dry run” for the attack he eventually staged in the Mandalay Bay. I don’t know. What could he have learned from spending time in a completely different building overlooking a completely different part of the city? A proper “dry run,” I would think, would have involved renting a room days or weeks before the event you’re actually targeting and surveying the shooting angles from the windows.

If this is true, it seems more likely that Paddock was prepared to make this concert his target but then chose to back out for whatever reason.

The gunman who murdered at least 59 people at a country-music concert on Sunday might have originally targeted another Las Vegas music festival held the previous weekend, according to a senior law enforcement source.

Stephen Paddock rented multiple condos overlooking the annual Life Is Beautiful Festival, which this year was headlined by Lorde and Chance the Rapper, said the source, who is not directly involved in the investigation but has been briefed on its progress.

The source suggested that Paddock may have lost his nerve or simply changed his plans and checked into the Mandalay Bay Hotel on September 28.

It’s hard to come up with an innocent explanation for why Paddock, who wasn’t known to have close friends apart from his girlfriend, would have needed multiple rooms. Chances are he wasn’t bringing the boys out to Vegas for a weekend of fun at the festival; he probably wanted multiple condos so he’d have multiple positions to fire from, just as he had at Mandalay Bay. So much as well for the theory floating around that Paddock targeted the Jason Aldean concert because he had a special grievance against country music fans, whether because they’re more likely to be right-wing or because Paddock himself was allegedly a country fan who wanted to kill like-minded people for whatever weird reason. The Life Is Beautiful Festival is geared towards pop and hip-hop fans.

One possibly important thing to note about the festival is that it’s spread out across a neighborhood in downtown Vegas. You can see a map of this year’s event here. All in all, it encompassed 18 city blocks and featured multiple stages for music. Maybe Paddock couldn’t find rooms to rent with a good view of any of the main stages and concluded that the festival grounds were so sprawling that it’d be hard to find concentrations of people penned in anywhere as sitting ducks otherwise. Once he started firing, victims could flee the area in all directions. The Aldean concert was much more concentrated, in one city block. Particularly if Paddock suspected his aim would be erratic using “bump fire,” he’d want a tightly packed crowd to maximize casualties.

As for the great motive mystery — nope, still no leads as I write this:

“All of the normal indicators that we would normally see, people two or three days later say, ‘A-ha, now I understand, I know what was going on in this guy’s life,'” Van Zandt said on “TODAY.” In Paddock’s case, “we don’t know.”…

Investigators said his residence in the desert community of Mesquite, northeast of Las Vegas, didn’t immediately turn up notes, emails or social media postings explaining his actions, but a computer from the home was found.

He did apparently gamble at least $160,000 in the weeks before the attack but whether that was unusual for him or whether he won more than he lost or vice versa is still unclear.

A creepy little curio that’s emerged online today are videos taken inside Paddock’s suite at Mandalay Bay — not by Paddock himself, and not after the shooting. These are videos taken by guests who, by chance, stayed in Room 32-135 in the past and recorded panoramas of the room on their phones, so impressed were they by the views it afforded of the Strip. CNN has posted one on its website although I can’t find an embeddable version. The clip below also purports to be of the same room. I believe that’s the concert ground visible briefly at 1:35.