Blood Justice by Rayven T. Hill
When sixteen-year-old Jenny James goes missing, and the local police are unable to find her, the girl's frantic mother hires private investigators Jake and Annie Lincoln to search for her daughter.
When the body of Jenny's boyfriend is discovered, the mystery of her disappearance deepens. Shaken out of their comfort zone of Internet searches and poring over public records, the couple soon find themselves facing the frightening possibility they are looking for the latest victim of a serial killer.
As more bodies pile up, the town is gripped with fear. It seems no one is safe, and the Lincolns race to solve an impossible puzzle before they become the killer's next victims.