The Gregor Demarkian mysteries were recommended to me by
widgetfox some time back, and I have several on the shelves; this is the first in chronological order, an Armenian-American widower and FBI veteran who is co-opted by a wealthy family to investigate a suitably Byzantine series of murders. It was well described in beautiful detail of setting and character, but the family are almost all really unpleasant people (apart from one sister who is a best-selling fantasy novelist) and I guessed the culprit correctly at quite an early stage. I'll read the ones still on the shelf but not sure that I will seek out any more after that.