Stephen Booth's Cooper and Fry series set in the Peak District are a good read.
Booth worked as a journalist in the area and hung out with local police officers. He knows the area extremely well and this comes across in his writing. Some of the books taught me stuff I didn't know about the history of the Peak District ( we go walking there a lot) eg the huge numbers of planes from WWII which crashed there, and whose sites can still be seen. Interesting development of the relationship between the two main characters too as the series progresses.