Pathologist examines a body found in the desert.
The blistering deserts of southern Arizona have been littered with the scorched and desiccated bodies of more than 2,000 illegal border crossers in the past decade and a half. The grisly task of locating and identifying them falls to overwhelmed local coroners and tireless volunteers, who attempt to provide closure to devastated families.

Independent Lens: The Undocumented, Monday at 10 p.m. on PBS 6.

Arizona Spotlight host Mark McLemore interviews Marco Williams, the filmmaker behind The Undocumented, to find out how he went about telling the story.