I'm confused, do you mean the shooter didn't call LEO, or the aggressor didn't call LEO? Or both, and is that something you know, or conjecture? Did the shooter know exactly what he himself (shooter) was looking for, or are you saying the shooter knew what the aggressor was looking for?
I'm not being facetious with you, as you're a new member and I don't know you well enough to mistreat you (yet), but it's 2am where I am and apart from saying the shooter should go to jail, your meaning is otherwise unclear.
Oh, and welcome to the forums!