Die Around Sundown by Mark Pryor

Mark Pryor's Die Around Sundown is the first entry in a mystery series set in Paris during World War II, where a detective is forced to solve a murder while protecting his own secrets.

Summer 1940: In German-occupied Paris, Inspector Henri Lefort has been given just five days to solve the murder of a German major that took place in the Louvre Museum. Blocked from the crime scene but given a list of suspects, Henri encounters a group of artists, including Pablo Picasso, who know more than they're willing to share.