Boogie Was a Gent — Philip Lauben

Harold Boomgard had seemed a meek little man, working for a respectable company. So when he dies after collapsing in the washroom of a snackbar, there is nothing immediately suspicious about it. But his wife is certain her husband had never owned that flashy tie or dreadful hat... Investigating, Captain Homer Clay of Homicide finds that Harold's firm had closed almost a year ago - yet his income had risen considerably. As Clay uncovers Harold's activities, he also turns up more surprises.