A hair raising tool to track murderersFebruary 26th, 2008 - 11:32 am ICT by admin
New York, Feb 26 (IANS) Something as inconspicuous as a strand of hair could help police track movements of criminals or unidentified murder victims, a new study says. And that’s because the human hair actually records what one eats or drinks, said geochemist Thure Cerling, who led the study along with ecologist Jim Ehleringer.
Police in a small US community have, in fact, already used the technique to identify a murdered woman found in Salt Lake County in October 2000.
The new hair analysis also may prove useful to anthropologists, archaeologists and doctors, said Ehleringer.
The findings of the study have been published in Proceedings of the National Academy of Sciences.
“We have found significant variations in hydrogen and oxygen isotopes in hair and water that relate to where a person lives in the US,” he said.
Isotopes are forms of the same chemical element with different atomic weights. Stable isotopes are those that do not decay radioactively.
A single hair can help determine a person’s location during recent weeks to years, depending on the length of the hair sample and thus how much time it took to grow.
The scientists used the method to produce colour-coded maps showing how ratios of hydrogen and oxygen isotopes in scalp hair vary in different areas of the US.
The maps were based on isotope analyses of hair and water samples collected from barbershops and tap water in 65 cities in 18 states across the US.
Ehleringer also developed a method now being used by the US Drug Enforcement Administration to ascertain where cocaine or heroin were present inside a human body, based on variations in carbon, nitrogen, oxygen and hydrogen isotopes in the hair.
He also analysed hydrogen and oxygen isotopes to help track counterfeit $100 bills, based on the water used to grow the cotton with which the bills were made.
Detective Todd Park of Salt Lake County, who used the technique to identify the murdered woman, described it as “phenomenal” and said: “I think it will help the law enforcement community a great deal.”
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