Under The Midnight Cloak by S.Y. Thompson

Lee Grayson is a nature photographer whose father is a senator in New York. She's never felt close to him and her faith in people as a whole is lacking. She moves to the town of Harmon deep in the Adirondack Mountains after inheriting her great aunt's estate, but the local townspeople seem a little...off. Then she meets Ranger Jamison Kessler and learns there's a killer running rampant around the area. Jamison seems to be hiding things from her and Lee is starting to become suspicious. Lee discovers that her aunt was a central part of this community and that she possesses the woman's unique abilities. She and Jamison are falling for each other, but things take a turn for the worse when the murderer sets his sights on Lee and a cure for his condition which he believes her to be harboring. Their situation is further complicated by the fact that the killer isn't even human. Neither is Jamison.