They didn’t know who she was, where she had come from or how she got there. All police knew was that she had been murdered.
It was Oct. 8, 2000, and hunters in the area had helped detectives recover 26 bones, some hair, a T-shirt and a necklace from a shallow grave near I-80, west of the Great Salt Lake.
The woman they named Jane Doe has not been identified in eight years. But, with a new technology, scientists at the U have been able to pinpoint the woman’s movements for the last two years of her life by simply studying a couple of strands of her hair.
Two scientists at the U developed a technology that can indicate the general location of where a person drank water by looking at the isotope levels in a person’s hair. With that information, they were able to develop a color-coded water map to distinguish the types of water found in different general regions where a person stayed. Regions vary in size and sometimes overlap in states, said James Ehleringer, a professor of biology who conducted the study. And a person’s history depends on the length of their hair, he said.
“If you have long hair, we can find two, three, four years worth of history,” Ehleringer said. “For men with shorter hair, it’s usually a couple of months.”
With the new technology, police have now been able to figure out that the 17- to 20-year-old unidentified woman had moved around every two months before her death, travelling from the Salt Lake City area to Montana, Wyoming, Washington and Oregon. This pattern has helped police determine that she was most likely a runaway from the East Coast, said detective Todd Park at the Salt Lake County Sheriff’s Office.
Ehlringer came up with the idea for the study two years ago when he began collecting hair samples from salons in the 18 states his family visited during a summer roadtrip. They ensured that each city had fewer than 100,000 people to make sure the hair had come from locals and not tourists. From there, they researched the correlation between the hair samples, isotopes and tap water. Their findings were published online in the journal Proceedings of the National Academy of Sciences.
“Your hair is like a little tape recorder, taping away, telling stories on what you were doing,” said Thure Cerling, a professor of geology and geophysics and of biology, who also worked on the study.
Three years ago, the two professors co-founded IsoForensics, Inc., a company that uses stable isotope analysis of forensic substances to find slight variations in chemicals.
In the study, the researchers also looked at a hair sample from a person who moved from Beijing to Salt Lake City. The hair that person grew during the three months before they moved contained relatively high levels of oxygen and hydrogen, which meant there were high concentrations of those isotopes in Beijing drinking water.
In hair closer to the scalp that grew after the person moved to Utah, the concentrations of those isotopes dropped because of lower oxygen and hydrogen levels in Salt Lake City’s drinking water.
The researchers’ findings will also be used to help anthropologists and archaeologists in addition to the police department by using the method to find where Native Americans and Mormon settlers migrated.
“If we take it a little bit further, we can use it to learn it about animal migration,” Cerling said. “But that’s down the road.”
In the meantime, the researchers will continue to help the police department with criminal cases. With the new technology, Ehleringer said detectives can find more clues about unidentified victims and suspects. Police can also use the technology to check a suspect’s alibi depending on the region where a suspect said the were at the time the crime happened.
In Jane Doe’s case, Park plans to search through missing persons records using the researchers’ information in hopes of identifying her.
“It’s is probably the biggest step in finding what happened to the person, to go back and look at what they were doing before their death,” Park said. “This technology gives you another piece of the puzzle.”
Re-creation of unidentified woman found near Great Salt Lake in 2000. Scientists at the U have been able to retrace her steps before she was murdered by looking at the chemicals in her hair.