Blood Count (Artie Cohen Series #10) by Reggie Nadelson
Mid-December 2008. Barack Obama has just been elected; all New York is ecstatic, especially Harlem. On a freezing night a few weeks later, detective Artie Cohen gets a late call from his ex girlfriend, Lily Hanes, begging for his help. Lily has been living at the Louis Armstrong Apartments, one of Harlem's great buildings, while working on Obama's campaign; now her Russian neighbor, Marianna Simonova, has died, and Lily fears she's at fault and needs Artie's Russian connections. Over a weekend when the city is locked in by snow and cold, with the financial markets tanking, one after another people at the Armstrong die. Artie, out of his element, a white detective in a black world, is drawn inexorably into the realm of Sugar Hill and the Armstrong, where almost everybody except for the real estate developers seems locked in the past.
Working to solve the murders, Artie tries desperately to win Lily back. Blood Count is a murder mystery, a love story, and a tale about New York, race, real estate, money, and music, with an ending one could never predict.