Secrets of the Unadilla by Richard Sullivan

In 1930, a woman died in The Unadilla, an art deco apartment building in Manhattan. More than thirty-five years later, Robert Knight, an investigative reporter with a New York tabloid who now lives in the exact same building, is given an impossible case: find out if this woman was murdered and if so, whodunit? The closer Robert gets to discovering the truth, the closer he gets to becoming a victim himself.