The agents worked under the legal umbrella of the Osage tribal police, but as told in the James Stewart movie "The FBI Story," they desperately wanted to find a way to make the Osage killings a federal case.
Then an agent discovered Roan's body had been found on federally owned grazing land that had been leased out. It was a thin thread, but enough for the bureau to claim the case was federal.
The big break came when agents were able to make a deal with a McAlester prison inmate. Blackie Thompson had his life sentence commuted in exchange for testimony that Hale tried hiring him to blow up the Smith house, according to Andrew Warren in "Earning Their Spurs in the Oil Patch," which appeared in the summer 2006 issue of the "Chronicles of Oklahoma."
That added speculation that Hale may have tried hiring Spencer, as well, and then feared the outlaw leader would talk.
The first Hale trial ended with a hung jury. Another trial in federal court in Oklahoma City ended with Hale, Burkhart and a hired killer sentenced to life in 1929. Hale was paroled in 1947. Burkhart was paroled in the late Thirties, jailed again in 1946, and released in the mid-Sixties.
"It certainly was one of the biggest cases in the 1920s for the bureau," Fox said. "It was a violent-crime case, which was rare for us back then. More rare, because it was the first time we assisted tribal law enforcement."
Fox said the bureau would not be asked again to assist tribal police until after World War II.
Twenty Osage murders, though, remained unsolved. But, with the Hale conviction, the killings ended.
However, Chief Jim Gray, 46, of the Osage Nation, is not pleased with the bureau's role in breaking the case.
"It seemed like the FBI's focus was on that particular set of murders only," Gray said. "There were quite a number of suspicious deaths among the Osage going on."
Gray pointed out that non-Osage inherited so many headrights from the Osage deaths of the Twenties that today more than 25 percent of the Osage mineral rights are held by non-tribal members.