In TX you're under juvenile law until you are 19.
He turns 19 on April 11, so technically he could just end up with just a couple of months in juvey.
The prosecutors are of course moving to have this treated in adult court, and I can't imagine a judge disagreeing but tbh I don't know what's gonna happen anymore.
The entire "affluenza" defense, and the fact that it actually worked, is a disgrace.
....but the world goes 'round