[1] Reinhard Heydrich was appointed chief of the SiPo and was already head of the party Sicherheitsdienst (Security Service; SD) and the Gestapo.
[2][3] In 1936, the Hauptamt Sicherheitspolizei was founded by Himmler, in order to create a centralized command office under Nazi control of the German criminal investigation and secret state police organizations.
[4] Therefore, the central office of the national criminal police department, then known as the Reichskriminalpolizeiamt (RKPA), along with the central office of the Gestapo were integrated into the Hauptamt Sicherheitspolizei under Heydrich's overall command.
[6] The Hauptamt Sicherheitspolizei was officially abolished and its departments were folded into the RSHA.
[6] Hauptamt Sicherheitspolizei was organized as a central office with three branches.