I'm looking for an old 80's or 90's horror teen book.
The story is about a girl who's on a bus and meets another girl; one of the girls is good and the other bad. The bad girl kills the good girl and gets rid of her. She then takes over her identity and lives the previous girl's life.
On the cover of the book I believe there was a locket or something and the picture of the girl has her eyes scratched out and only the color red shows where her eyes should be and people can't understand how the eyes are scratched out without damaging the red backing paper.
I can't remember the title or author.