On 21 December 1975 she participated with the international terrorist "Carlos the Jackal" in a raid on the OPEC headquarters in Vienna. There she murdered two people: one was a 76 year old policeman interpreter named Anton Tichler and the other was a plainclothes Iraqi bodyguard who had grabbed hold of Kröcher-Tiedemann. While he was attempting to control her weapon, Kröcher-Tiedemann produced a second gun and shot the man through the head.