A romantic thriller about a girl who falls in love with a crazy boy with is a pale as a snowman

I read this book in the late 2000s early 2010s. It was a young adult style thriller. A young woman moves to a new town and falls in love with a mysterious boy who is very pale, which earned him the nickname of snowman. He slowly goes crazy and commits acts of violence and begins to stalk her. She talls her family and they try to inform the police but they are no help. I forget how it ends exactly, but she escapes him and he is not seen again. Thank you to anyone who helps me find this, the most difficult part is that I am confident the title was actually "snowman" but looking that up yields less than helpful results.