In fact all the MSM is going out their way to say there is absolutely no evidence of any motive. Seems to be setting the "we'll probably never know" meme. I keep coming back the Sheriff's "radicalized" comment. He didn't pull that out of the air. There's definitely stuff being held back.
That's not surprising. The typical person who does this has been dealt a losing hand by Lady Luck. And that's usually where the motive comes from - a desire to strike out at whatever forces are felt to be holding him down. Muslims want to kill the infidel stealing Muslim oil and corrupting Muslim women. McVeigh wanted to strike back at a murderous and oppressive federal government. And so on.
What's Paddock's excuse? I'd say this is going to be very similar to Sandy Hook - a psychotic break adapted to the personality of a very methodical, almost OCD individual.
He kept saying there must have been an accomplice. He's now rejected that theory, presumably based on security video. The typical perp that cops deal with have problems finding their rear ends, even using both hands and a flashlight. He's just not dealt with what a smart, accomplished individual can do just via a combination of research and figuring things out on his own. Paddock also had enough money to buy whatever he needed. The sheriff must have figured he needed financing to buy his gear.
We are fortunate there aren't more like him. By this, I mean we have plenty of smart guys, but very few who would do something like this.
Just my observation from listening, reading and watching from afar, this guy was like a lone wolf who acted under the radar as an embedded terrorist cell waiting for the right time and venue to carry out his attack.
But with all the government surveillance of Americans going on, it is surprising that investigators have not uncovered any inkling of a motive yet.