Most readers of classic mystery stories are very familiar with Rex Stout's marvelous Nero Wolfe novels and novellas. Wolfe, together with his sidekick and narrator Archie Goodwin, are among my own favorite characters. But Rex Stout also wrote some other mysteries, particularly in the late 1930s, featuring other detectives.
In 1939, Stout wrote "Red Threads," a book featuring Inspector Cramer of New York City's homicide squad, who is usually Nero Wolfe's foil, opponent, and occasional more-or-less-unwilling collaborator in the Wolfe/Goodwin books. "Red Threads" is outside that series, and Cramer appears as the principal police investigator of a murder - and, in fact, it is Cramer's clever use of the facts during an interrogation session that allows him to trap the murderer.
The book is distinctly non-politically-correct - the victim, principal suspect and other key characters are "American Indians," and there is a fair amount of stereotyping. However, once you get by that (and Stout, to his credit, doesn't share those attitudes and makes that pretty clear), "Red Threads" is a pretty good suspense story.
Unlike the Wolfe stories, always narrated by Archie Goodwin, "Red Threads" is written in the third person, from the points of view of several characters. Most of the actual investigation is carried out by one suspect and the woman who believes he is innocent. Cramer, as usual, is on the wrong trail for most of the book, but again, to his credit, he is quick to acknowledge his mistakes and to thank the amateurs publicly for their help in solving the mystery.
"Red Threads" has been out of print for a while, but there are a lot of links from this Amazon page to second-hand bookdealers who can provide mostly-inexpensive reading copies. If you enjoy the Wolfe saga, "Red Threads" isn't at the same level (in my opinion), but it's certainly worth reading.