Do You like book Requiem Mass (1999)?
This is the first book in the DCI Andrew Fenwick series and details some pretty explicit and gory murders. The clues lead back to a group of schoolgirls and a sudden death 20 years before and Fenwick is pitted against a seemingly invincible and ruthless perpetrator. If you can suspend your disbelief over the occasional copper's hunch, coincidence, lucky break, etc, this is a very good read, gripping and interesting right to the end with its twist in the tale. One strange point. Elizabeth Corley, for me, writes men better than she writes women who are often vaguely sketched in the book while the men are much more realistic.
—Ellen