Raymond Chandler [1888–1959]
The High Window [1942]
From Wikipedia:
The story begins (in the pre-war summer of 1941) when Mrs. Elizabeth Bright Murdock hires Marlowe to find an old rare coin, the Brasher Doubloon, that belonged in her deceased husband's collection. Mrs. Murdock insists that her son's wife has stolen the coin. Marlowe begins investigating, but quickly finds himself entangled in a series of unexplained murders.
http://en.wikipedia.org/wiki/The_High_Window