From Washington, D.C., at a meeting of the American Academy of Forensic Sciences
Aerial surveys that scan the ground at many wavelengths, some visible and some not, may offer a way to quickly and easily detect clandestine mass grave sites.
During field tests in Costa Rica, Margaret Kalacska, a remote-sensing analyst at Simon Fraser University in Burnaby, British Columbia, and her colleagues buried several slaughtered cattle—a weight approximately equal to that of eight adult humans—in a hole 5 meters square and 1.5 m deep. In smaller holes nearby, they buried single carcasses. Yet another hole was filled with nothing but soil.
One month later, team members scanned the sites from a high-flying jet at narrow bands of wavelengths ranging from 400 nanometers (blue light) to 2,500 nm (shortwave infrared radiation). The carcass-containing plots clearly stood out from other areas, especially at some infrared wavelengths, Kalacska says. Ground-based o