Sleeman, Susan. Shadow lake survival #2

"Rookie officer Sydney Tucker can handle threats to her life. After all, she's a law enforcement officer. Even when a killer demands she turn over evidence from a drug bust or he will kill her, she refuses to comply. But things change when he threatens the life of her teenage sister, and Sydney might consider turning over the evidence. If she had what he was looking for. But even when Sydney tells the killer that she doesn't possess the evidence, he doesn't believe her, and his threats continue. Emerson County Sheriff Russ Maddox steps in, putting Sydney and her sibling under his watchful eye. But will his protection be enough? The killer is closing in, picking off the people and places that mean the most to Sydney. A list that now not only includes her but Russ as well