The Ivory Grin by Ross Macdonald 1973 Paperback

A hard-faced woman clad in a blue mink stole and dripping with diamonds hires Lew Archer to track down her former maid, who she claims has stolen her jewellery. Archer can tell he's being fed a line, but curiosity gets the better of him and he accepts the case. He tracks the wayward maid to a ramshackle motel in a seedy, run-down small town, but finds her dead in her tiny room, with her throat slit from ear to ear. Archer digs deeper into the case and discovers a web of deceit and intrigue, with crazed number-runners from Detroit, gorgeous triple-crossing molls, and a golden-boy shipping heir who\u2019s gone mysteriously missing.