They were shoting in the hallway.How did they get in the school with a mask on?
“They were shoting in the hallway.How did they get in the school with a mask on?”
Only a guess, but -
The person(s) got buzzed in because they were routine visitors known by the school, maybe a parent or school lunch salesperson, and the mask was hidden underneath the coat. In this weather a heavy coat would obviously not be suspicious.
Then, once inside,...