Satan and A Priest

This story seems like a Dan Brown novel. A priest alleged to have conducted satanic rituals. A nun brutally murdered. Her body found in a hospital chapel with an altar cloth draped over it. No DNA or physical evidence linking the main suspect, the priest of the church, to the crime. An upside down cross etched into her skin. The weapon of choice, an envelope opener. 26 years the case went unsolved until a few unlikely advocates take on the power of the church. Here is the link. I will now write the book.