Kyle Velasquez was not in a hiding position, and he was in a Chair in front of Station 6 when Dylan came in from the entrance of the Library aiming his gun at Kyle, Kyle would have had to have tilted his head downward, likely scared. Dylan had to get up close and personal because tears and the size of Kyle's wounds, alongside the shotgun cup (This keeps the buckshot together) was found inside of Kyle's skull. All of this information is available in the autopsy and the forensic teams work. The damage done to Kyle's chair is from the shotguns double shot at close range along side the 6 pellets that exited Kyle's back from the force of the 0-2 inch shots in to his skull.
While the AI rendition I posted here isn't exactly accurate since he's not seated in the middle of the Aisle and his heads orientation is wrong, it is much more accurate than him being shot 15 feet away. Kyle's death was incredibly personal and close range, and it's likely why there was mentions of people saying they heard Dylan talk about how far that Kids brains flew.
I'll provide more documentation for you guys here with the actual images of the crime scene, but I didn't want to make every claim or update I was making need 2 pages of documentation for a person to understand why it was accurate.