Friedel, a vegan animal rights activist, harbored animosity toward the murder victim, sausage manufacturer Rolf Wiener. He denies committing the crime, however. The widow, Sylvia Wiener, tells the police about threatening letters the sausage manufacturer had received some time ago. At the factory, marketing director Paula Wolf shows the police the threatening letters and leads them to a research lab.

There they meet employee Johannes Rudzic, who states that Jens Friedel threatened him with a barbecue fork. Pathologist Caroline Fuchs confirms that such a fork could be the murder weapon. She also found a broken wine bottle at the crime scene.