14 DAY TRIAL // The stink expelled by a corpse could tell much about its history, even how the person was eventually murdered.
Now, researchers got a scientific research that could be a tool in detecting hidden graves.
30 compounds were specifically linked by the scientists to buried human corpses.
Improving training of dogs to discover concealed bodies and possible development of electronic noses that sniff out human remains would speed body hunting, which is crucial in forensic investigations. "The faster you can find graves, the more evidence you can recover," explained researcher Arpad Vass, a forensic anthropologist and research chemist at Oak Ridge National Laboratory in Knoxville, Tennessee.
Vass and his team at Anthropological Research Facility keep constantly some 30 buried corpses in various states of decay at the roughly three-acre facility, investigating the odors they spread. The corpses are either from volunteers donating them for science or were donated by next of kin.
The analyses of volatile gases gathered by perforated pipes above and in the soil above and below the body have detected some 478 different compounds in four years of research.
The stinky odor needs about 17 days to be detectable on the soil surface, in a case where a corpse is buried about 18 inches (45 cm) deep. "The average clandestine grave is about 2 to 2-1/2 feet ( 66 to 80 cm ) deep, according to statistics from the FBI," Vass explained.
Scientists found detectable compounds even after 17 years of decay. "Even bone has odor," Vass said. Moreover, "you can even tell apart different species of animals based on the odor."
30 simple molecules were found fit for forensic research: they are specific to buried human bodies, are consistently detectable over an array of soil types and depths. "The most interesting ones are the fluorinated ones," said Vass. "We think these come from a lifetime of drinking fluorinated water and incorporating fluorine into our tissues and bones. As the body breaks down, it releases these compounds, which are very easily detected, since they are very light and come up through the soil easily."
Investigators pointed that "cadaver dogs" may be expensive to train and maintain, and the accuracy varies from individual to individual. "They're very good when they work, but they're living, breathing creatures, and they can get tired," Vass said.
Ground-penetrating radar, used to detect corpses, can be tricky to use and requires labor intensive and are hard to cover extensive areas. This research could help the design of "electronic noses", which are currently used for other tasks, to detect dead bodies without dogs. "The idea is to have a handheld walkie-talkie-type device, with a snorkel at the top that draws air in with a pump, to concentrate and then analyze samples," Vass said.