he was a former khmer rouge child soldier and leader of a gang of looters.w who we had met. i knew that he was important. i knew that many people were telling me he was the best. and i knew that he was feared. >> why were people afraid of him? >> you know, over the years, he had killed many people. >> reporter: it turned out toek tik had worked for decades supplying latchford with thousands of treasures and he was amazed to see them again in latchford's books. >> he kept opening the book and going back to the front cover and going through and tapping and saying, i know this one, i know this one, i know this one. >> when he says he knew this one, it means he helped loot those ones? >> that's what we learned later, yeah. >> reporter: toek tik became a key confidential source for gordon's team. they gave him a code name, lion, to protect his identity and followed him to dozens of temples where he confessed what he'd found and how he'd stolen it. >> he would say to us, i'm going to transfer everything in my head to you. i'm going to tell you everything, every se