By 1944, the organisation had more than 400,000 members, making it the largest police force in Germany.[37] Kriminalpolizei ("Criminal Police"; Kripo) were the criminal police of Nazi Germany. The agency's employees were mostly plainclothes detectives and agents, and worked in conjunction with the Gestapo.[38] It was under the command of Arthur Nebe of the Reichskriminalpolizeiamt (which later became Amt V of the RSHA) until 1944. In the last year of its existence, Amt V was commanded by Friedrich Panzinger, who answered to Kaltenbrunner.[39][40] Sicherheitspolizei ("Security Police"; SiPo) was the criminal investigation security agency of Nazi Germany.