So it turns out that, in 2018, two teens were arrested while making plans to shoot up a junior high in Uvalde. Their ages are similar to this shooter's, but information is scarce on the ground. LINK:
https://www.mysanantonio.com/news/lo...s-12882042.php
Edit: In this article, the editor's update note specifically says this shooter is not one of the two previously arrested for planning a shooting:
https://www.kens5.com/article/news/c.../273-548565605
Is this another Parkland, where law enforcement absolutely failed at its job? The reports coming out now are fucking wild.