Police and security forces available included the Geheime Staatspolizei (Gestapo), Ordnungspolizei (Orpo), Kriminalpolizei (Kripo) and Sicherheitspolizei (SiPo). In addition, the Nazi intelligence organization, the Sicherheitsdienst (SD), investigated and performed security checks on people, including party members. If the SD personnel determined an arrest was to be made, they passed the information on to the Gestapo.