Detectives in a lab determined she was a tall woman, likely of Native American descent. And she was killed in modern times - her teeth showed evidence of fillings and other dental work far too advanced for this to be a pioneer-era killing. But that's where the trail runs cold.
Kentucky State Police Detective Chad Winn isn't even sure where the woman is from or how she got to a remote area of Barren County, about 95 miles south of Louisville. He speculates she was dumped there.
Such an unusual killing has authorities wondering if the woman was the victim of a hate crime, Winn said. Mexican drug cartels are also known for beheading and scalping people in turf wars south of the border, though that kind of brutality has yet to be seen in rural Kentucky. Without more evidence, those theories remain pure speculation.
"I'm not saying there's no connection tying violence here to the cartels," said Jim Balcom, the Drug Enforcement Administration agent overseeing Kentucky, who is not involved in the investigation. "I'm just saying we can't do it at this point."
The mystery began about a year ago when a group of students, searching the woods for a rare tree, found the top of a skull in a drainage ditch near the Cumberland Parkway about eight miles east of Interstate 65. Investigators then found bones scattered across a 100-foot area - Winn guessed that was because of animals and water runoff moving them.
Since then, Winn and a team of investigators have been trying to identify the woman, where she came from and how she ended up on the side of a road. What little they do know was determined by forensic anthropologists who helped gather and examine the bones.
The woman was unusually tall, standing at least 5 feet 9 inches and perhaps as tall as 6 feet 1 inch, said Dr. Emily Craig of Georgetown, Ky., who works with NamUs, the National Missing and Unidentified Persons System. Craig said enough bones were found to determine that the woman was of Native American descent, between 20 and 50 years old, and was killed and exposed to the elements sometime between 1999 and 2010.
However, that doesn't necessarily mean the woman identified herself as Native American. And she may have been from outside of Kentucky, Winn said. The state has no federally recognized tribes, and only 0.3 percent of the population - about 12,000 of the state's 4 million residents - identify as Native American, according to U.S. Census figures.
"There are features in the bones that have racial characteristics," Craig said. "We're pretty sure of her ancestry. How she self-identified, we don't know."
The practice of cutting off someone's scalp dates back centuries and is known in the U.S. for its role in warfare between some Native American tribes and settlers. Modern scalping cases are rare in the U.S. but not unheard of: In 1997, a man was convicted of killing and scalping a mentally disabled friend in Massachusetts. And in 2005, a woman in Idaho was sentenced to 10 years in prison for scalping a teenage friend. The victim in that case survived.
In this case, markings on the skull led to the determination that the woman was scalped. Craig wouldn't talk specifically about what led to the conclusion, but she said a team of anthropologists agreed on the result. And there was no doubt this was a modern killing because the woman had root canals and two alloy fillings in her teeth, Craig said.
"Not everybody has that kind of dental work," she said.
Details of the remains have been entered into NamUs, which compiles information about missing persons as well as unidentified remains. Kentucky - which is more aggressive about reporting cases than many other states - has 49 open unidentified remains cases in NamUs and 131 missing persons in the NamUs system. Nationally, there are about 8,600 sets of unidentified remains and missing persons in the system, said Todd Matthews of Livingston, Tenn., a spokesman for NamUs who has spent much of his life investigating cases of unidentified remains.
So far, investigators have ruled out that the bones were those of a Michigan woman missing since 2004. Dental X-rays of the woman found in Kentucky are still being checked against records of missing persons.
"Often you find out who someone is by eliminating who they are not," Matthews said.
Investigators also have tapped the National Crime Information Computer; the FBI's Violent Criminal Apprehension Program, known as VICAP; multiple tribal police departments; and the federal Bureau of Indian Affairs. All those wells ran dry, Winn said.
"We're at a dead end," he said.
The remains have been sent to the University of North Texas Center for Human Identification in Fort Worth. The center is a project of the National Institute of Justice, which helps law enforcement officials with missing persons and unidentified remains cases.
Dixie Peters, the technical leader for the missing persons unit at the center, said technicians will try to pull DNA from any remains sent by law enforcement. Peters couldn't speak directly about the Kentucky case, but she said once a DNA profile is available, it will be compared to all other cases in the system. But getting a match requires a family member or friend to come forward with a sample to put in the database, Peters said.
"The only way we're going to make a comparison is if we actually have something to compare it to," Peters said.
How long such a search will take is "the million dollar question," Peters said. While the center has no backlog for testing in cases of unidentified remains, it could take up to three months to extract DNA and run the results through the various databases, Peters said.
Winn, who works out of the state police Bowling Green post, is hoping someone remembers seeing or meeting the woman or that a relative comes forward. Winn is speaking in some detail about the case now, saying investigators have run out of leads and hoping that something about the woman or the circumstances brings in tips.
A DNA match may be the only way to solve the mystery.
"We're at a crossroads," Winn said. "We've had no luck."