The Osage Indian murders were a series of murders of Osage in Osage County, Oklahoma, during the 1910s–1930s. Newspapers described the increasing number of unsolved murders and deaths among young adults as the Reign of Terror. Most took place from 1921 to 1926. Some sixty or more wealthy, full-blood Osage persons were reported killed from 1918 to 1931. Newer investigations indicate that other suspicious deaths during this time could have been misreported or covered-up murders, including those of individuals who were heirs to future fortunes. Further research has shown that the death toll may have been in the hundreds.The tribe had retained mineral rights to the land of their reservation. Each tribal member had what were known as headrights to the mineral rights on communal land. When valuable oil was found on their land and leases were sold for oil production, each member with headrights was paid a share of the lucrative annual royalties for leases by oil companies. In 1906 and subsequent years, United States Congress passed a series of laws, ostensibly intended to help the Osage retain their wealth, that created a system of guardianship for "minors and incompetents", as determined by and under the jurisdiction of Oklahoma's local county probate courts. The Oklahoma courts routinely found American Indians to be incompetent without considering mental capacity. For example, a guardian was appointed for one Indian woman on the basis that her savings suggested a lack of spending which was evidence that she did not understand the value of money. Many guardians used their appointment to gain control over the ward's wealth for their own personal benefit.During this period numerous white men married Osage women to become guardians of their estate. Some of the murders were committed in order for some whites to take over the headrights of Osage members when inheriting property after deaths. The Osage found minimal assistance from local law enforcement to investigate the deaths, as it was dominated by powerful whites working in their own interests. Later investigation, including that of the Bureau of Investigation (BOI, the precursor to the Federal Bureau of Investigation) revealed extensive corruption among local officials involved in the Osage guardian program, including lawyers and judges. Most of the murders were never prosecuted. Nevertheless, several perpetrators were convicted of murder, including William Hale, a powerful rancher who ordered the murders of his nephew's wife and other members of her family to gain control of their headrights and oil wealth. Two other perpetrators implicated with Hale, Henry Grammer and Asa Kirby, died under suspicious circumstances during the BOI investigation. Several others involved were convicted of lesser charges, such as perjury, witness tampering, and contempt of court, for attempting to impede the investigation. In 1925, the U.S. Congress changed the law to prohibit non-Osage from inheriting headrights from Osage with half or more Native American ancestry, in an effort to protect the Osage. The U.S. government continued to manage the leases and royalties from oil-producing lands. Over decades, the tribe became increasingly concerned about these assets. In 2000, the Osage Nation filed a suit against the Department of the Interior, alleging that it had not adequately managed the assets and paid people the royalties they were due. The suit was settled in 2011 for $380 million and commitments to improve program management. Source: Wikipedia (en)