Chief prosecutor Kai Graeber wears a face mask prior to the beginning of the trial on allegations of organized doping practices against Mark S. (not in the picture) in a courtroom in Munich, Germany, 16 September 2020. The Erfurt-based German physician Mark S. has supposedly provided illegal performance enhancing blood transfusions as a well-organized service to some 21 athletes from various disciplines, several of whom have confessed. His practice was uncovered during the multinational Investigation ‚Operation Aderlass‘ (Operation Bloodletting) after doping admissions by an Austrian cross-country skier in February 2019.