«The Chemistry of Death» by Simon Beckett

When the bizarrely mutilated and long-dead body of a young woman is found in a ditch in Manham, an isolated and insular village in the Norfolk marshlands, it isn't just the fact that she had been a friend that disturbs Dr David Hunter. He was once a high-profile forensic anthropologist and all too familiar with the different faces of death, until a devastating personal tragedy made him turn his back on his former life and career.
Now hidden away as a country doctor, Hunter's past is a secret he hopes will remain buried. So when he's asked by the police to use his arcane skills to help track down the killer, he's reluctant to become involved, knowing this will only stir up the painful memories he's been trying so hard to forget. Then another young woman disappears, and Manham is plunged into a fog of fear and paranoia that threatens to tear it apart. And no one seems exempt from suspicion as the twisted killings continue. And as the once peaceful community is riven by fear and mistrust, David Hunter realises it will take all his knowledge and expertise if the killer is to be stopped. But not even he is prepared for the terrible cost that will exact - or the awful price that failure threatens to bring…