What Kind of Clues Is Peblis Working With to Trace the Bodies That He Has?

Bodies have been in the water for weeks, if not months. Getting across that river is really difficult for people who aren't knowledgeable about it. Sometimes you'll meet people who say they tried to cross the border and were pushed back by greek police or something like that. So basically, he has what he finds on their body that hasn't disintegrated, and and he sifts through them.