 A couple of years later, he took over the role the Lord Goring in Oscar Wilde's "An Ideal Husband" in the playhouse Bochum under the direction of Armin Holz.Koch had his first TV appearance in 1980 in the 77th episode of the series "Derrick", followed by an episode in the popular crime series "Tatort" in 1986.He acted in numerous thrillers like "Der Mann mit der Maske", "Die brennende Schnecke" and in 1997 in Heinrich Breloer's two-piece ", in which he portrayed the role of Andreas Baader.