Marie Brand und der Liebesmord (2017)

Jennifer Winkler, a co-owner of the online dating agency “Amore Grande,” is found dead. What initially looks like heart failure while jogging turns out, after the autopsy, to be murder. The killer deliberately injected insulin into a vein in her neck. Detective Marie Brand and her colleague Jürgen Simmel begin investigating. They first question co-owners Karsten and Christian Wenke, who immediately accuse their former employee, Ben Seidel. Seidel is shocked to hear of his ex-girlfriend’s death. He gives the investigators a lead on Dietrich Degenhardt, a bitter rival in the online dating market. He recently lost a lawsuit against Jennifer Winkler and is now facing serious financial problems. Marie Brand soon discovers that Degenhardt is diabetic and therefore knows how to inject insulin. However, after a thorough investigation, she does not believe he is the killer. Jürgen Simmel finds a connection to a case from the past, in which another young woman was injured by an insulin injection and has been in a coma ever since. She, too, was a client of “Amore Grande,” so the killer may have been selecting victims through the platform. Marie Brand therefore tries to set a trap for him and quickly creates an online profile with the dating agency. After she has “weeded out” several candidates, she shortlists Dr. Steffen Gruber. But although she has not arranged another date with him, he lies in wait for her in the underground parking garage. The detective flees in a panic and is shortly afterward incapacitated by an insulin injection. Fortunately, Jürgen Simmel comes to her aid and gets her to the hospital in time. While Marie Brand is convinced that Gruber is the killer, Ben Seidel has also begun to suspect Gruber and believes he murdered his ex-girlfriend. As Seidel tries to apprehend him, he sprays him with tear gas. Gruber then panics and tries to flee by car, accidentally running Seidel over. During questioning, it emerges that Gruber did not kill Jennifer Winkler—his wife did. She had discovered that her husband was cheating on her and, afraid that he might leave her, had simply eliminated his online girlfriends. When Sabine Gruber attempts to kill her next prospective victim, she is stopped in time and arrested.