Niki Herzog is the first female officer in the history of the show. She is played by Elke Winkens. She is paired with Hoffmann (Kunz is almost entirely desk-bound in this incarnation of the series), and sexual tension constantly results. The pair had spent the night together, before starting their new jobs, without realising that they are both police officers. They soon share a house (with Rex) and are often disturbed in the middle of a romantic moment with news of a case.
In contrast to Hoffmann, Herzog tends to be more level-headed and capable of performing physical acts. Her physical appearance also serves the team well in relating to suspects, as she is frequently underestimated and sometimes taunted by brash male criminals.
In the season 10, she only appears at Email from the Murderer. she leaves without explanation. However, she still appears in the opening of the three last episodes of the Austrian series.