The Shadows in the Street (Simon Serrailler, #5)

Serrailler has just wrapped up a particularly exhausting and difficult case and is on sabbatical on a far-flung Scottish island when he is called back to Lafferton by the Chief Constable. Two local prostitutes have been found strangled. When the wife of the St. Michael's Cathedral Dean goes missing and then another respectable woman is taken on her way to work, the townspeople grow angry and afraid. Serrailler is in the greatest danger of his life.