While my colleagues were sitting down to the office canteen’s Christmas lunch yesterday, I was down at London’s Geological Society looking at powerpoint slides of decaying corpses. Christmas may come once a year, but it’s only every other year that the Forensic Geoscience Group holds a conference.
The obscure discipline of forensic geoscience has exploded in the last decade, says Laurance Donnelly, who organized the meeting, “Geoscientific Equipment & Techniques at Crime Scenes”. Geologists help solve crimes in two ways, he says: they find things buried underground – handguns and murder victims, for example; and they analyze samples of soil and other minerally stuff – one memorable presentation featured an expert in construction materials and a bloody brick. Mark Harrison, representing the UK National Police, reminded the assembled experts, “You’re either helping us to find a scene or you’re helping us match someone to the scene.”
To suss out burials, geologists have been adapting methods and equipment long used to prospect for oil, gas and minerals. Ground-penetrating radar proves particularly useful, presenters said, in finding both buried guns and buried pigs. The pigs are proxies for human corpses, whose use in these experiments is forbidden by UK law, and researchers have been burying them since the 1970s. But the animals are still being interned, along with pH, temperature and moisture sensors, to put some numbers on how their decay over time alters various types of graves.
Other earth-scanning technologies can detect international law-breaking, including the mass graves of war criminals. Geoscientists are, in fact, preparing to perform the inspections that will enforce the nuclear test ban treaty, assuming it is ever ratified. Their first full-scale field exercise in finding a buried-and-detonated nuke was held in Kazakhstan this September. One major finding was that the protective suits annoyingly impeded scientists’ surveying skills.
We also heard from boosters of analytical geophysics. Miniature Raman spectroscopes may be coming to a border near you, said Howell Edwards, to perform 10 second scans that ID drugs, explosives and ivory. And trace chemical elements found on scenes and suspects could be matched, Nelson Eby explained, using a technique called instrumental neutron activation analysis that requires a research-grade nuclear reactor. One of his proof-of-concept experiments showed that maple syrup varies in its elemental profile depending on its source – highly useful, he speculated, for “the case of the pilfered pancake”.
But the lower-tech scrutiny on display was even more impressive. Joining the soil experts was forensic ecologist Patricia Wiltshire, who clearly needs a TV show. Using only a trained eye and a high-quality light microscope, Wiltshire and her team can look at the pollen, spores and plant pieces on a piece of cloth and vividly describe where it’s been – because every latitude and longitude, every soil type and every suburb, is botanically unique.
Wiltshire also showed the least appetizing corpse photos of the day. Merry justice to all!