Paul,
although the majority of the graves is situated outside Germany, the Volksbund Deutsche Kriegsgräberfürsorge also lists persons on German war cemeteries. At least I found a victim of my paternal family buried at Traunstein. However, I'm unable to say how many persons there are in their database, who are buried inside Germany. Therefore it should make sense for many fellow researchers to consult this Volksbund database in order to verify if there is an entry or not. Be aware, however, that this collection of data does not list literally every person that was killed by war measures.
In addition, I would like to draw your attention to the fact that the Volksbund people offer a photo service for every cemetery worldwide they are in charge of. For a symbolic fee of about 3 U.S. dollars, you can receive a photo of your relative's grave. Please allow several weeks for delivery as photos are taken during routine inspections. Please refer to http://www.volksbund.de/grabschmuck/ for the details.
Regards,
Jörg