Inspiration from Strangers

This is a clip from the trailer of the 2008 film 'Strangers'.
The female character is standing in the middle of the room and we see the killer silently walk into view from behind the wall. The woman is still unaware that he is there and continues to stand in  the middle of the room. We are going to use a similar shot in our opening sequence when the girl is standing in the hallway and is unaware that the killer is behind her.