The Sicherheitspolizei (Security Police), often abbreviated as SiPo, was a term used in Nazi Germany to describe the state political and criminal investigation security agencies. It was made up by the combined forces of the Gestapo (secret state police) and the Kripo (criminal police) between 1934 and 1939 and was headed by Supreme Commander Heinrich Himmler, but the term continued being used informally until the end of the Third Reich. As such, it was directly under the control of the SS.