While I haven't followed the Uvalde story very closely - I'm a human with ordinary bandwidth, like most - I think it would be true to say that had laws been followed with the Parkland shooter, he would not have passed a NICS background check, and thus not been able to buy his gun at a licensed store. I suspect that people in his area knew enough about him that finding a private seller willing to sell to him might have been difficult.
It sounds like the Uvalde shooter had a poor reputation in a fairly small community (about the size of the nearest town when I was growing up).
But speaking more generally, several notorious mass shootings have involved failures to follow laws that would have led to the shooters being unable to pass a background check.
The shooter bought 2 AR-15 rifles and 375 rounds of 5.56 a couple days before the shooting -- legally. He bought the weapons a day after his 18th birthday and the ammo a day or so later.
Here's another development:
Texas school principal suspended after Uvalde shootingBy Brendan O'Brien - 4h ago
(Reuters) - The principal of the Texas elementary school where a gunman went on a rampage in May has been suspended with pay, her attorney said on Tuesday, two weeks after a damning report about lax security that enabled the shooter to carry out the attack.
Mandy Gutierrez, principal of Robb Elementary School, was placed on administrative leave by Hal Harrell, the Uvalde school district superintendent, on Monday, her attorney Ricardo Cedillo told Reuters.
He offered no specific reason for the suspension which comes two months after the massacre, which killed 19 schoolchildren and two teachers.
The shooting opened up a new wave of debate over the easy access to guns enjoyed by Texans and many other Americans.
https://www.msn.com/en-us/news/us/texas-school-principal-suspended-after-uvalde-shooting/ar-AAZZlBs"Ms. Gutierrez has no further comment at this time," he said.