Tatort S2013E20 - Lürsen - 28 - Er wird töten

Stedefreund (Oliver Mommsen) is back from Afghanistan! But before Chief Inspector Inga Lürsen (Sabine Postel) can be happy about it, she has to deal with a threatened woman (Annika Kuhl) in the presidium, who keeps saying "He will kill". When Stedefreund wants to get Inga's new colleague Leo Uljanoff (Antoine Monot jr.), he makes a horrible discovery: Leo was murdered in the police station. The search for the killer begins. Although Inga had a love affair with Leo, she wants to solve the case. Reunited , Inga and Stedefreund start the investigation. They find out that the woman is the doctor Marie Schemer. She accuses her ex-husband Joseph (Peter Schneider) of following her, threatening her and killing their little daughter and now Leo.
In fact, there is a connection: Leo led a case involving the death of Joseph and Marie's daughter eight years ago. At that time Joseph was convicted of killing the child. Is that why Leo was murdered?