The Light in the Ruins by Chris Bohjalian

This historical tale is set in the 1940s, with an alternating viewpoint jumping ahead to the 1950s.  The Rosatis are an Italian family of noble lineage who believe that they are safe behind the walls of their ancient villa as war rages across Europe.  The youngest daughter, Christina, spends her days swimming in the pool, playing with her young niece and nephew, and wandering aimlessly amid the estate's gardens and olive groves.  But when a German and Italian soldier arrive at the villa asking to see an ancient Etruscan burial site, the Rosatis' tranquility is shattered.  Christina is courted by a young German lieutenant, Nazis descend upon the estate, and what was once their sanctuary becomes their prison.  In 1955, Serafina Bettini is an investigator with the Florence Police Department who is battling her own demons.  A beautiful woman who carefully hides her scars and buries her haunting memories of the war, she is assigned a new case about a serial killer who is targeting the Rosatis and murdering remnants of the family one by one.  When she starts digging into this, she finds that her own tragic history is interwoven.  Bohjalian does a good job jumping back and forth in time, and the character development and history of the time period are well crafted.  It is a story of human frailty when confronted by moral paradox told well and set amongst the exquisitely rendered Italian countryside.