Dr Clyde Snow is widely considered to be the father of forensic anthropology.
Now 81 years old, he has had a long career examining graves around the world and testifying against the likes of Saddam Hussein and the American serial killer, John Wayne Gacy.
Lately, he has worked extensively with human rights groups, particularly Americas Watch.
Dr Snow spoke to the BBC's Dan Collyns in Lima, Peru, where he had been testifying in a trial:
First broadcast 12 July 2009