U.S. Fish and Wildlife Forensics Lab Director Ken Goddard holds a wood sample used in the lab's forensic work in Ashland, Ore. Jes Burns/OPB/EarthFix hide caption

itoggle caption Jes Burns/OPB/EarthFix

Dallas Mildenhall, New Zealand's forensic pollen expert, peers at samples through a microscope. Courtesy of David Wolman hide caption

itoggle caption Courtesy of David Wolman

Knight (left) and Bucheli take soil samples from beneath one of the decomposing bodies. Katie Hayes Luke for NPR hide caption

itoggle caption Katie Hayes Luke for NPR

A Thai medic checks bodies for forensic identity in Phang Nga province in southern of Thailand on Jan. 11, 2005. Thousands of people were killed in Thailand after a massive tsunami struck on Dec. 26, 2004. Pornchai Kittiwongsakul/AFP/Getty Images hide caption

itoggle caption Pornchai Kittiwongsakul/AFP/Getty Images