The title refers to a lunar phase that coincided with the blooming of the oil plant, which the Osage considered sacred. The murders were carried out by a network of white accomplices, including local officials, doctors, and businessmen, who used poison, bombing, and staged deaths to gain control of Osage headrights and royalties. The investigation uncovered an estimated 60 or more deaths, though the true number remains unknown because many cases were ruled accidental or natural. The case exposed deep corruption in local law enforcement and the justice system. It also led to reforms in federal investigative authority and tribal sovereignty protections.
Who Were the Real Victims and Perpetrators
The primary victims were Osage tribal members who held mineral rights, known as headrights, which entitled them to a share of oil royalties. Many were murdered between 1921 and 1926, with the most prominent case being the bombing of Ernest Burkhart's wife, Mollie Kyle, and her family. Ernest Burkhart was a white ranch hand and nephew of William Hale, a powerful cattleman who orchestrated the murders to gain control of the Kyle and Brown families' headrights. Hale and several accomplices were eventually convicted in state and federal courts, though many other suspected perpetrators were never prosecuted. The case drew national attention after newspapers reported on the mysterious deaths and the extreme wealth of the Osage.
The U.S. Congress later launched investigations into the Osage guardianship system, which had allowed non-Native guardians to control Osage finances and assets. The hearings revealed widespread exploitation, fraud, and coercion against Osage landowners. The Bureau of Investigation's role in solving the murders helped justify its expansion into a federal law enforcement agency. The case also highlighted how legal loopholes and biased local courts enabled the murders. Today, the Osage Nation continues to manage its mineral estate and seeks accountability for historical losses.
How Accurate Is the Film Compared to the Real Events
The film stays close to the documented facts in Grann's book, using real names, trial transcripts, and historical records. It accurately depicts the role of William Hale, Ernest Burkhart, and the Bureau of Investigation agent Tom White, who led the undercover operation. The movie compresses some timelines and combines minor characters for narrative clarity, but the central murders, motives, and outcomes are factual. The film also shows how the Osage were systematically stripped of their wealth through guardianship fraud and contract killings. It highlights the broader pattern of dispossession faced by Native American communities during the oil boom.
Critics and historians have noted that the film understates the scale of the violence and the number of unsolved deaths. The real investigation involved hundreds of interviews, exhumations, and covert surveillance, some of which are not shown on screen. The movie also does not fully explore the long-term legal and financial impact on the Osage Nation, which still manages mineral revenues today. For deeper context on the Osage history and the FBI's role, see the official FBI historical overview