Having been suspended in 1999 for review, the exhibit reopened in 2001 under the name "Crimes of the German Wehrmacht: Dimensions of a War of Annihilation 1941–1944".

He worked as a radio writer, in the 1970s and as a lecturer at the University of Bremen, and from 1980 to 1985 as a dramaturge and director at the Deutsches Schauspielhaus in Hamburg and the Städtische Bühnen in Cologne.

The committee's report in 2000 stated that accusations of forged materials were not justified, but some of the exhibit's documentation had inaccuracies.

In the works "Vom Verschorben der Täter" (2004) and " Hitler war's" (2005) he examined the tendency to present the history of National Socialism as a story of "acts without perpetrators".

Starting in 2006, Heer investigated the expulsion and persecution of artistic and technical personnel in Nazi Germany for racial and political reasons as part of the exhibition project “ Silent Voices ” using the opera houses in Hamburg, Berlin, Stuttgart, Darmstadt and Dresden .

He also reconstructed the history of the defamation and marginalization of Jewish artists at the Bayreuth Festival from 1876 to 1945 and recalled the fate of 51 persecuted people after 1933.