I heard a reference made by one of the parents of the dead that there was a video of the hallway, as he told of his daughter fleeing, being shot nine time in the back during which her spine was severed. I haven’t seen any on-scene video like that, either.
Sadly your comment reminds me of the scene in the recent 15:17 movie where the young man stands by the door ready to confront the shooter with nothing more than a ball point pen and explains “I didn’t want word to get back to my family that I died hiding under a desk”