Wicked Souls by Katie Wismer

Something is wrong with Valerie Darkmore.
She may have made it through her initiation into the Marionettes, but she’s quickly learning that was only the beginning. Everything she used to know has changed, including maybe herself.
Adjusting to her new reality proves to be the least of her worries when bodies appear all over the city, and the death toll continues to rise. She can’t count on her partnership with a dangerous vampire prince to be enough to save her. Because while they’re investigating the attacks, the killer might just be looking for her too.