Siegfried Hausner (24 January 1952 – 5 May 1975) was a student member of the German Socialist Patients' Collective who was sentenced to three years imprisonment in 1972 for terrorist related crimes. When he was released in 1974, like many other former members of the SPK, he joined the Red Army Faction. Stockholm Embassy siege. In 1975 Hausner was handpicked by Siegfried Haag to lead the group, known as Kommando Holger Meins who conducted the West German Embassy siege in Stockholm to force the release of 26 of his RAF comrades. Hausner was in charge of the wiring of the explosives.
https://en.wikipedia.org/wiki/Siegfried_Hausner