Ninety years ago, the most devious serial killer this nation has ever seen was captured by the FBI after a long, arduous, and often very dangerous investigation. The Bureau of Investigation at that time was in its infant stages, and didn't even bear the name "FBI". It's newly appointed director, J. Edgar Hoover, threw everything he had--and that wasn't much in the early 1920's--at the bizarre and troubling series of murders bedeviling the Osage Indian tribe of Oklahoma.
The Osage history is unique and ironic, in that they were once--by complete accident and actions of the white man---the wealthiest people on earth. This sudden and unexpected wealth put them in the crosshairs of a murder conspiracy that confounded law enforcement for years, until the federal government sent in a team of investigators to try and figure out what was going on out West. I should add that serial killers almost always use the same method to kill. Bundy strangled his victims, and Son of Sam shot them. But these Indians were dying by different means, including poisoning, and explosions. The idea that one person was carrying out the murders became less and less likely. Forensic examinations were needed, but forensics were brand new, and the agents of that era were raw. The idea of "training" was something new Hoover was just beginning to instill, and the men who went out to investigate the Osage murders were selected largely on character alone. Agent Tom White headed up the case. With very little resources, he courageously uncovered a network of racism, oil money, and greed, and a conspiracy of fear that could rival any Mafia family.
To get all the gritty details, read Killers of the Flower Moon (see link at right), by David Grann. It's a heart-wrenching but fascinating story that could only have happened in these United States, and Grann tells it expertly.