Mary Ann Shaffer only ever published one book and it was after her death. That's a shame, as it was such a delightful book, you crave more. It's not a mystery, but a series of letters between people during the German occupation of Guernsey in the aftermath of WWII. I think you'd enjoy it. Check out http://www.guernseyliterary.com

Here is a link to the BBC Inspector Lynley series. The actor that plays him is named Nathaniel Parker and he looks better in these still shots than he does in the show. Just not what I pictured in my mind - less sophisticated and more smarmy.

http://www.bbc.co.uk/drama/lynley/characters/inspectorlynley_person_page.shtml