Lucifer's Tears by James Thompson

Inspector Kari Vaara has taken a job with the homicide squad in Helsinki at his American wife Kate's urging. While Kari is happy to leave his hometown of Kittila after the traumatic events of his last case, he has unhappy memories of his previous time as a cop in Helsinki. His co-workers now like neither him, nor his partner, Milo Nieminen. Kari and Milo are investigating the death of Iisa Filippov, who has been brutally murdered in her lover's apartment. Both Kari and Milo believe that her husband had something to do with her death, but are told by the national chief of police to leave him alone. Kari is also asked to interview ninety-year-old Arvid Lahtinen about possible war crimes he committed during World War II. When given the case, Kari learns that his favorite grandfather worked alongside Arvid and probably was involved in the atrocities, too. To complicate matters further, Kari's brother-in-law and sister-in-law have come to Finland to stay with him and Kate while they await the birth of their first child. While reading Lucifer's Tears, I found it hard to put it down. Even better than the first book in the series, Snow Angels, with more insight into Finnish culture and history.