Hi - we can recommend loads set in the North East of UK. Your best starting point is Mari Hannah, new author, 2 books out:
Settled Blood is her latest, set along Hadrian's Wall, Durham and Pennines. Crime. The first was the Murder Wall, Corbridge and Newcastle (I have just done a blogpost on her latest novel)
Flying with Kites is part set Newcastle by Alan Reynolds
The Other Family, Joanna Trollope part set NE
The Quality of Mercy Barry Unsworth
The First Time I saw you Hazel Osmond
Wedlock by Wendy Moore
Wife in the North, Judith O'Reilly....
Anyway loads more, depends on their reading taste. Have fun choosing.