P. D. James was an English novelist, best known for her mystery series featuring policeman and poet Adam Dalgliesh. Those I've read are all set in some kind of closed society -- an adaptation of the "closed room" mystery. She also has two mysteries starring Cordelia Gray, stand-alone novels, and non-fiction books.
She passed away in 2014, at age 94, still writing books and serving as a Life Peer in the House of Lords.
I've now read ten of James's books. Unusual for me, I read nine with my ears. The audio editions are particularly good and readily available from my library.
Those I have read are in red; those currently on my TBR shelf are in blue.
ADAM DALGLIESH MYSTERIES
Cover Her Face (1962) (country house)
A Mind to Murder (1963) (private mental hospital)
Unnatural Causes (1967) (writers' colony)
Shroud for a Nightingale (1971) (nursing school)
The Black Tower (1975) (reviewed here) (adult care home)
Death of an Expert Witness (1977) (forensic lab)
A Taste for Death (1986) (parish church)
Devices and Desires (1989) (community with a nuclear power plant)
Original Sin (1994)
A Certain Justice (1997)
Death in Holy Orders (2001)
The Murder Room (2003)
The Lighthouse (2005)
The Private Patient (2008)
CORDELIA GRAY MYSTERIES
An Unsuitable Job for a Woman (1972)
The Skull Beneath the Skin (1982)
Innocent Blood (1980)
The Children of Men (1992)
Death Comes to Pemberley (2011)
The Maul and the Pear Tree: The Ratcliffe Highway Murders, 1811 (1971), with Thomas A. Critchley
Time to Be in Earnest: A Fragment of Autobiography (1999)
Talking About Detective Fiction (2009)