In the early 1920s, dozens of members of the Osage tribe—instantly wealthy after the discovery of oil on their reservation—were systematically killed in one of the most shocking murder conspiracies in American history. In his new book, “Killers of the Flower Moon: The Osage Murders and the Birth of the FBI,” best-selling author David Grann chronicles how greed, oil and prejudice resulted in a sinister plot and the Federal Bureau of Investigation’s first major homicide case.

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