 He was tried in a German court for incitement to commit intentional homicide, for his role in the deaths of people who tried to flee the GDR between 1971 and 1989.On 16 September 1993, Kessler was found guilty of manslaughter and was sentenced to seven-and-a-half years in prison.Kessler filed an appeal to the European Court of Human Rights, claiming that his actions were in accordance with GDR law and meant to preserve the existence of the GDR.