The professor of the university Kai Berger has been found dead by shooting in his office by his secretary: it seems that he knew the murderer. The commissioner spoke with his wife who doesn't know very much about the activities of his husband as advisor for private companies. The autopsy reveals that the professor had intimate relations before his death. Also the police knows that Kai Berger was killed by a Browning: he had such a Browning revolver and used to keep it in his desk at the university. Finally his main private client is Mr. Ewald Lübcke who manages a pharmaceutical company.
—zutterjp48