Wikipedia
The Reichssicherheitsdienst (RSD, lit. " Reich security service") was an SS security force of Nazi Germany. Originally bodyguards for Adolf Hitler, it later provided men for the protection of other high-ranking leaders of the Nazi regime. The group, although similar in name, was completely separate from the Sicherheitsdienst (SD) which was the formal intelligence service for the SS, the Nazi Party and later Nazi Germany.
Its role also included personal security, investigation of assassination plots, surveillance of locations before the arrival of Nazi dignitaries and vetting buildings as well as guests. The RSD had the power to request assistance from any other SS organisations and take command of all Ordnungspolizei (order police) in its role protecting the Nazi functionaries.