plot, and brother Bryan hired accomplices to murder Kyle family heirs. They arranged for the murders of Kyle's mother, two sisters, a brother-in-law, and a cousin, in cases involving poisoning, bombing, and shooting. With local and state officials unsuccessful at solving the murders, in 1925 the Osage requested the help of the Federal Bureau of Investigation. It was the bureau's first murder case. By the time it started investigating, Kyle was already being poisoned. This was discovered and she survived. She had inherited the headrights of the rest of her family. The FBI achieved the prosecution and conviction of the principals in the Kyle family murders. From 1921 to 1925, however, an estimated 60 Osage were killed, and most murders were not solved. John Joseph Mathews, an Osage, explored the disruptive social consequences of the oil boom for the Osage Nation in his semi-autobiographical novel Sundown (1934). Killers of the Flower Moon: The Osage Murders and the Birth of the FBI (2017) by David Grann was a National Book Award finalist; a related major motion picture is in development. Changes to law and management claims As a result of the murders and increasing problems with trying to protect Osage oil wealth, in 1925 Congress passed legislation limiting inheritance of headrights only to those heirs of half or more Osage ancestry. In addition, they extended the tribal control of mineral rights for another 20 years; later legislation gave the tribe continuing communal control indefinitely. Today, headrights have been passed down primarily among descendants of the Osage who originally possessed them. But the Bureau of Indian Affairs has estimated that 25% of headrights are owned by non-Osage people, including other American Indians, non-Indians, churches, and community organizations. It continues to pay royalties on mineral revenues on a quarterly basis. Beginning in 1999, the Osage Nation sued the United States in the Court of Federal Claims (dockets 99-550 and 00-169) for mismanaging its trust funds and its mineral estate. The litigation eventually included claims reaching into the 19th century. In February 2011, the Court of Federal Claims awarded $330.7 million in damages in partial compensation for some of the mismanagement claims, covering the period from 1972 to 2000. On October 14, 2011, the United States settled the outstanding litigation for a total of $380 million. The tribe has about 16,000 members. The settlement includes commitments by the United States to cooperate with the