I'm going to guess that the person in the social media posted on the other (now closed) thread is the older brother of the shooter (who possessed older brothers ID) and the guy that came out of the woods (now in custody) is probably the shooters friend. Just pure speculation on my part.
If either the AL on Twitter or RL on Facebook have found out this way that their mother, her whole class and possibly father have been killed, I really feel for them as well.
This is all so awful.
Editing to say: that's not to take anything away from the known victims of this dreadful situation, I just wonder if there is a case of stolen identity here which could mean that fake names have been given and the real people have just found out their mother and father are dead.