Unknown soldiers

52 years after he died in a Vietnam plane crash, Raul Guerra's memorial service was held at Risher Mortuary in Montebello, Cal.
Libby Denkmann / American Homefront

Raul Guerra was adopted, so his DNA couldn't be matched to blood relatives. Scientists instead turned to an emerging technique that linked his bones to the drinking water in the places he grew up.

A VA cemetery crew lifts a steel casket from the ground containing remains of an unknown U.S. service member, more than six decades after it was buried.
Jay Price / American Homefront

Using DNA and other new technology, scientists hope to identify the remains of more than 600 U.S. service members buried in a Hawaii veterans cemetery.