Aug. 5, 2013
The latest big thing in forensics is a technique called “stable isotope analysis,” a process that allows scientists to analyze a human body’s hair – or fingernails or bones – to find out where its owner has been living or travelling.
by Liz Porter
In November 2006, a badly beaten man of Asian appearance was dumped at the accident and emergency section of a hospital in the Welsh county of Gwent, in the UK. The victim died shortly afterwards, without ever speaking. So police were desperate to discover who he was – and why he had been attacked.
Frustratingly, none of the usual modern forensic methods could help. Neither the man’s fingerprints nor his DNA profile matched any UK records. If he had been a recent arrival, there should have been a record of him entering the country, but there wasn’t.
But police had one last forensic tool at its disposal: a 21st century technique hailed as “the next big thing” after DNA and known as “stable isotope profiling” or “stable isotope ratio analysis.”
This technique involves scientists analyzing a human body’s hair – or fingernails or bones – to find out where its owner has been living or travelling. Often summarized as “you are what you eat and drink – and where you eat and drink,” stable isotope profiling is based on two key facts. The first is that our hair and bones show traces of the water we have ingested in food and drink. The second is that water sources from different geographical areas can be chemically distinguished from one another.