Reichskriminalpolizeiamt (RKPA), was Nazi Germany's central criminal investigation department, founded in 1936 after the Prussian central criminal investigation department (Landeskriminalpolizeiamt) became the national criminal investigation department for Germany. It was merged, along with the secret state police department, the Gestapo, as two sub-branch departments of the Sicherheitspolizei (SiPo). The SiPo was under Reinhard Heydrich's overall command. In September 1939, with the founding of the Reich Security Main Office (RSHA), the SiPo as a functioning state agency ceased to exist as a department and was merged into the RSHA.