Let Me In (2010)

Chloe Moretz (Hit Girl from Kick-Ass) stars as Abby, a secretive 12-year old girl, who moves next door to Owen (Kodi Smit-McPhee, The Road). Owen is a social outcast who is viciously bullied at school and in his loneliness, forms a profound bond with his new neighbor. Owen can’t help noticing that Abby is like no one he has ever met before. As a string of grisly murders occupy the town, Owen has to confront the reality that this seemingly innocent girl is really a savage vampire.