"Killers of the Flower Moon: The Osage Murders and the Birth of the FBI" (Doubleday), by David Grann

The FBI burnished its reputation by gunning down Depression-era gangster John Dillinger and bringing to justice the kidnapper of Charles Lindbergh's baby. However, a more challenging but long forgotten investigation a decade earlier gave the fledgling agency its first major success.

At least two dozen and perhaps as many as several hundred Osage Indians were murdered during what became known as a yearslong "Reign of Terror." The shocking episode that unfolded on the high-grass prairie during th...