P1 - a guess at a possible location of the perp when MB entered the halls - would be in a recessed area into the doors into the auditorium (same with P3 area). On that previous map, the kitchen area is off the map, up top.
If you're trying to connect location of body, with kitchen door exit, here's another map making it easier to visualize.
A red line shows an unseen-by-cam path from one proposed body location, to the kitchen door.
A purple line shows an unseen-by-cam path from another proposed body location, to the kitchen door.
I have added c3, in far right end of northside hall (NE corner of building), to show where the closest known cam is in that hallway. I'm theorizing it didn't detect motion that far away, and thus didn't record, when perp exited.