Muddies the water a bit, doesn't it? I don't know any details about either kid other than the reports that they were both special needs, but anyone who has worked in education like yourself, or anyone who is the parent of a special needs kid like me, can form a general picture of what might have happened here. It's a tragedy all around. If the comment above that this kid threatened to do this very thing before turns out to be true, the school is going to be in some trouble and rightfully so.
Special needs services at public schools in Texas are in dire shape. Between the well-intentioned but ultimately negative impact of inclusive classroom policies and the complete lack of funding, hiring of qualified individuals to work with these kids, etc. we're dealing with today, something has to change and dramatically. I wish I had any answers.
EDIT TO ADD: Sorry if this gets a bit cloakroom-ish, but no group is suffering from state leadership's attack on public schools more than the special needs kids. Everyone from the Abbott to Morath to their buddies looking to profit from what's going on, can get fucked and die slowly over a fire, as far as I'm concerned. If there is a hell, people who fuck with special needs kids will be first in line.