The Dead of Night by Elaine Viets

When Angela Richman finds two dead bodies in a cursed crypt on Halloween, she is drawn into a spine-tingling mystery. Has a Chouteau Forest legend turned deadly, or is a dangerous killer on the loose?
Everyone in Chouteau Forest knows the legend of the Cursed Crypt. It's claimed that the restless spirit of a professor nicknamed Mean Gene Cortini, buried in Chouteau Forest University's crypt, has been causing death and destruction in the Forest for almost two centuries.
Local residents are used to disease and natural disasters striking every seven years. But not murder. When Trey Lawson outbids the wealthy Du Pres family at the university's annual Howl-o-ween Benefit Auction, he wins the chance to spend the night in the crypt with his fianc�e, Lydia. Angela Richman, Death Investigator, finds their mutilated bodies there the following morning.
As Angela investigates, she learns that Trey was threatening the established hierarchy of Chouteau Forest. Has the legend taken a deadly turn, or are Trey and Lydia victims of a vicious power struggle?