Erwin Kowalke is a specialist in his field. He started working for the German War Graves Association (VDK) in 1980 and ever since he has travelled to the last battlefields of the World Wars to do his job. He is actually retired these days but he continues to volunteer for the organization, which has located, identified and buried German soldiers since 1919. And Kowalke's expertise is in demand. After the Balkan wars of the 1990s, he spent months in the former Yugoslavia uncovering and identifying bodies.
An extensive article (in English) in the Spiegel Online on Erwin Kowalke can be found here.