FINDING bodies buried in unmarked graves can be extremely difficult, but lasers might be able to help.
To find out, Katie Corcoran at Oak Ridge National Laboratory in Tennessee and her colleagues dug shallow pits and buried corpses of individuals who had donated their bodies for research. They used quick pulses of laser light, or lidar, to make a 3D scan of the area before the bodies were buried, and then scanned again one day later and then after four months and 21 months.
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The first of these scans revealed that the grave surface became elevated by a few centimetres shortly after burial. It then shrank back down again between the second and third scans (Forensic Science International, ).
The decrease in elevation was probably caused by the bodies decomposing in the first few months, creating more room for the soil to settle, say the researchers.
The results show that investigators could narrow down possible locations in the months after a grave is dug by taking two or more lidar scans, which can be done from the ground or even an aircraft.
This article appeared in print under the headline 鈥淟asers used to bring up the bodies鈥�