The Hanging Cage (The Northminster Mysteries Book 4) by Harriet Smart
The two main characters, Major Giles Vernon, and the police surgeon Felix Carswell are engaging, and the story moves swiftly. There are also some good subplots that add to character development.
Although I started with the fourth book in the series, I found I could read it without confusion. However I enjoyed it so much, I've already bought the first book of the series.
Great find, I'm looking forward to the rest.