Complex sentence: From 1933 he served as an SS- "Truppführer" in Carinthia and would join the "Sicherheitsdienst" (SD) in 1934.
Split into simpler sentences: From 1933 he acted as an SS- "Truppführer" in Carinthia. He would join the "Sicherheitsdienst" (SD) in 1934.