We don't know who the target was, we can't ask him because he's dead. However his mom worked there as a teacher, was killed along with most of her class.
He doesn't seem to have a child and it's unclear who else he killed at a secondary location.
But the death total is...
6 Adults at the school
18 Kids at the school
2 kids at the hospital
1 adult at some place in town
His brother is from NJ, that explains that screw up.