What is that movie in the VERY beginning there was a girl who got killed in the bathroom stall?

She went to the bathroom and the crazy guy came in and was smelling her between the stall and then killed her?.....the rest of the movie was,i think its like an (independent film) where there is a girl that runs away from home with her boyfriend, and they stop in the woods at this "police" cabin thing (where the girl in the beginning was) and the boyfriend goes and looks for whatever he heard in the woods, and never comes back, then the girl is just waiting for him for about 2 days and she calls this police man on the intercom radio thing in the cabin and turns out the cop was the killer who tortured her boyfriend and sewed his mouth shut and the girlfriend thought he was the killer and killed him then saw his face and realized it was her boyfriend....i saw this movie about 2 years ago in greece, but its an american film...ughhhhh HELP!