He was a commander of the Trautenau-Parschnitz camp. He participated in World War I, serving in the 153rd and 264th Infantry Regiment. From early 1940 to January 30, 1941 he held an unspecified role in the Division IV camp Flossenbürg KL, where then was transferred to the post of commander of one of the camp guard companies.
The camp moved to the headquarters staff of Hinzert concentration camp, where he was adjutant to the commandant of the camp, Paul Sporrenberg. On June 18, 1943 he moved to KL Lublin. In early 1944, he was moved to KL Gross-Rosen where from May 1944 to February 13, 1945 he was company commander and the head of sub Parschnitz in Pozici and AL Trautenau in Trutnov in the Czech Republic.
He was arrested by Soviet forces on January 1, 1946. On March 25, 1946 he was sentenced to death by a Soviet Military Tribunal, a special form of a court-martial. On May 14, 1946, Ritterbusch was executed at an unknown place.
In November 2002, his trial was revisited by the Main Military State's Attorney of Russia and the sentence was confirmed.
He was a member of the Sturmabteilung, NSDAP on January 25, 1925 (six card number 317) and SS from 1931 (Registration No 9 107).