If you need any further evidence that his plot was months in the making, this would be it. But you shouldn’t. Paddock reportedly began his gun-buying spree last October and the logistics of his attack at Mandalay Bay had obviously been carefully thought out. The guy didn’t decide three days before to kill a bunch of people. He built an arsenal, chose a room that would give him a window onto the Jason Aldean concert, set up cameras, meticulously brought his guns into the hotel a few at a time in multiple bags, and then pounced. He had explosives in his car. No one would be surprised to learn that he’d had something like this in mind for a full year now.

Besides, we already had reason to suspect that he scouted other locations for an attack. Two days ago the Daily Beast reported that he rented an apartment overlooking the Life Is Beautiful festival held last week in downtown Vegas. Now USA Today and TMZ are reporting that he booked a pair of rooms in July overlooking the main stage at Lollapalooza in Chicago. And so we have a new layer of mystery on top of the one about motive: How long had he been planning mass murder, and why didn’t he attack sooner? Was it as simple as cold feet?

Las Vegas gunman Stephen Paddock booked rooms in a Chicago hotel facing the Lollapalooza music festival in August, a law enforcement official told USA TODAY on Thursday.

Paddock, 64, booked one room at the Blackstone Hotel starting Aug. 1, two days before the festival opened. He booked a second room Aug. 3…

Investigators analyzing Paddock’s computer, cellphone and other electronic devices have found no obvious ideological motive, no clear connection to extremists or activist groups or outward display of mental illness.

Note the plural: “Rooms.” TMZ also has evidence that Paddock booked not one but two rooms:

Both rooms had an August 6 checkout … that’s when Lollapalooza ended.

The hotel directly overlooked the main stage as well as several adjoining stages. It also overlooks the main entrance and exit where thousands of people file through. And the hotel had a bird’s-eye view of the crowd. We’re told Paddock specifically requested both rooms be a “view room” which only face Grant Park, where the concert was being held. And here’s the scariest part … it’s difficult if not impossible to flee because of Lake Michigan. Sources tell TMZ Paddock had never booked a room at the hotel before, nor had his girlfriend.

My theory for why he might have passed on an attack on the Life Is Beautiful festival was the sheer sprawl of the event, which spread out over 18 blocks. People might have been able to flee in all directions fairly quickly. Look at TMZ’s map of Lollapalooza and you’ll see that the area’s more penned in, exactly as a killer would have wanted it. But Paddock never showed in Chicago. Reportedly he also researched hotels around Fenway Park in Boston but never booked any there, possibly because there are no hotels in the vicinity with a clear view of the crowd.

Why two rooms at the Chicago hotel? Remember, he also rented “multiple condos” overlooking the Life Is Beautiful event, per the Daily Beast, even though he was — presumably — alone. The theory for why he wanted a suite with two rooms at Mandalay Bay was because he wanted to fire at the crowd *and* at the jet fuel tanks, which would have been a more difficult shot from the window overlooking the concert. But there were were no jet fuel tanks at Lollapalooza or at the LIB festival. Did he have an accomplice, as the Vegas sheriff suspected last night? Or did he simply want more windows onto the fleeing crowd once the shooting started? As people ran left or right from the killing ground he may have wanted to “follow” them as far as he could by moving from one room to another.

As for why he passed on Lollapalooza and chose the Aldean concert, I wonder if that was a simple matter of needing to stay in his comfort zone. He was a gambler by profession; he knew Vegas intimately. Even a lunatic bent on an attack like this would be bound to feel some anxiety over flaws in his plan, details he might have missed. On familiar turf in Vegas, that apprehension would be less acute. And if it’s true, as the sheriff suggested last night, that Paddock had some harebrained scheme to escape with his life, naturally he’d want to be in a city he knew well rather than one like Chicago that was stranger to him. Familiarity could even explain why he passed on the Life Is Beautiful event and targeted the Aldean concert instead. He was familiar with Mandalay Bay, having gambled there many times, and the familiarity may have helped him work up his courage. It’s not the *event* that was key to his decision to attack, perhaps, but the site from which he staged it.

Here’s one of Paddock’s victims discussing her brief encounter with Trump yesterday in the hospital.