Checking the girls room
A few minutes later, he and ten other officers break into the home and handcuff the person who had initially opened the door. Sebastian goes straight upstairs to the room where the girl was constantly waving from. He needs to be aware of what took transpired.
Why she was not waving that day
He can hardly believe what he sees as he opens the door. He can now see why she stopped waving at him on that particular day. But what had happened to the girl? Why did Sebastian have such a strong sense that something was wrong and would be revealed to be true?