Forensic Mysteries #1: The Christopher Killer book by Alane Ferguson

Fascinated by forensics, seventeen-year-old Cameryn Mahoney persuades her father, the county coroner in sleepy Silverton, CO, to take her on as his assistant. But she never expects her first case to involve the death of a friend! Rachel Geller, a beautiful young waitress, is found strangled in a field with a Christopher medal around her neck—clearly marking her as the fourth victim of a serial killer. Cameryn is determined to help find Rachel’s killer, and attending the autopsy gives her the first clue. But as she follows her instincts and gets closer to the killer, Cameryn suddenly finds herself on the verge of becoming his fifth victim!