By Peter Wood
At the BA Science Festival
Researchers have revealed how a team of forensic experts used pollen to help them to convict Bosnian war criminals.
Pollen provided a vital clue linking burial sites
Professor Tony Brown of the University of Exeter used the method to link mass graves in Bosnia, which supported the case for genocide by the prosecution.
He says pollen and unchanging soil characteristics can "provide strong circumstantial evidence placing a vehicle or person at a crime scene".
The research was presented at the BA's annual Festival of Science in Exeter.
"Forensic pollen analysis has made a significant contribution to the investigation of war crimes in Bosnia," Professor Brown explained.
Bosnian war criminals tried disguising their acts of genocide by exhuming mass graves and reburying bodies in smaller graves, claiming they were the result of minor battles.
The prosecution at the UN war crimes tribunal needed to show that the many "secondary" burial sites could be linked to a few "primary" ones, to prove that mass graves had initially existed.
Professor Brown was part of the North East Bosnian Mortuary Team which conducted forensic examinations of mass graves. The team, which worked under constant UN guard, examined 20 sites over a four-year period from 1997.
Soil samples were taken from skeletal cavities, inside the graves, and from around the suspected primary and secondary burial sites.
Pollen from the soil samples was cleaned with powerful chemicals before being analysed, and the mineralogy of the soil itself was examined.
Once complete, matches could be made between different samples - ultimately leading to links between primary and secondary burial sites.
Professor Brown said: "For example, one primary execution and burial site was in a field of wheat. When bodies were found in secondary burial sites they were linked to the primary location through the presence of distinctive wheat pollen in soil recovered from the victims."
Independent ballistics work was in 100% agreement with the conclusions of the pollen and soil analysis, he added.
Overall, the work formed a significant component of the generic body of evidence used against those involved in the Srebrenica atrocities.
Professor Brown said a case in point was the conviction of Radislav Krstic, commander of a military unit which participated in the massacres in and around Srebrenica in the summer of 1995.