Question: Who was the leader of the secret police of Nazi Germany?

full_context: Document 1: Belgrade Special Police: The Belgrade Special Police (, SP UGB) was a Serbian collaborationist police organisation directed and controlled by the German Gestapo (German: "Geheime Staatspolizei" ) in the German-occupied territory of Serbia from 1941 to 1944 during World War II. It grew out of the Belgrade General Police of the interwar period, which had a significant role in the suppression of the Communist Party of Yugoslavia after that organisation was banned in 1920. Eighty per cent of work of the SP UGB related to suspected communists. It initially had a responsibility to investigate other groups, such as the Chetniks of Draža Mihailović, but ended up cooperating with Mihailović's Chetnik movement. The SP UGB had significant autonomy in who it arrested, tortured and interrogated, and who it sent to the Banjica concentration camp, but did not have the power to release prisoners from the camp, a power which was retained by the Gestapo. The SP UGB exchanged information with a number of different agencies, including the German military intelligence service, the "Abwehr", and other collaborationist organisations such as the Serbian Volunteer Corps.
Document 2: Ernst Röhm: Ernst Julius Günther Röhm (] ; 28 November 1887 – 1 July 1934) was a German military officer and an early member of the Nazi Party. As one of the members of its predecessor, the German Workers' Party, he was a close friend and early ally of Adolf Hitler and a co-founder of the "Sturmabteilung " (SA, "Storm Battalion"), the Nazi Party's militia, and later was its commander. By 1934, the German Army feared the SA's influence and Hitler had come to see Röhm as a potential rival, so he was executed during the Night of the Long Knives.
Document 3: Sicherheitsdienst: Sicherheitsdienst (] , "Security Service"), full title Sicherheitsdienst des Reichsführers-SS (English: Security Service of the Reichsführer-SS ), or SD, was the intelligence agency of the SS and the Nazi Party in Nazi Germany. The organization was the first Nazi Party intelligence organization to be established and was considered a sister organization with the Gestapo , which the SS had infiltrated heavily after 1934. Between 1933 and 1939, the SD was administered as an independent SS office, after which it was transferred to the authority of the Reich Main Security Office ("Reichssicherheitshauptamt "; RSHA), as one of its seven departments/offices. Its first director, Reinhard Heydrich , intended for the SD to bring every single individual within the Third Reich's reach under "continuous supervision."
Document 4: Heinrich Baab: Heinrich Baab (born 27 July 1908-?) was a secretary and Gestapo chief of Frankfurt at the Lindenstrasse station. The Gestapo (Secret State Police) was the official secret police of Nazi Germany and German-occupied Europe. After the war in Europe ended, Heinrich Baab received a sentence of life imprisonment in March 1950 for his involvement in the Final Solution as the head of Division IIB2. He was imprisoned from 1948 to 1973. On 6 April 1950 he was convicted of murdering 55 Jews from 1938 to 1943 and the attempted murders of 21 Jews, as well as for maltreatment of 29 Jewish prisoners in Frankfurt. His trial was five weeks long, with 157 witnesses testifying, including some of his victims. Heinrich Baab sent many of Frankfurt's Jews to camps from the rail station. Baab's supervisor at the Lindenstrasse station was Oswald Poche. Before joining the police in 1928 in Stettin, Baab was a locksmith. Heinrich Baab's SS membership number was 306631 and his Nazi Party number was 1346669.
Document 5: Arthur Ehrhardt: Arthur Ehrhardt (21 March 1896, Mengersgereuth-Hämmern, Saxe-Meiningen – 16 May 1971) was a Waffen-SS officer and author on warfare who became a leading figure in the post-war neo-Nazi movement.
Document 6: Schutzstaffel: The Schutzstaffel (SS; also stylized as with Armanen runes; ] ; literally "Protection Squadron") was a major paramilitary organization under Adolf Hitler and the Nazi Party (NSDAP) in Nazi Germany, and later throughout German-occupied Europe during World War II. It began with a small guard unit known as the "Saal-Schutz" (Hall-Protection) made up of NSDAP volunteers to provide security for party meetings in Munich. In 1925, Heinrich Himmler joined the unit, which had by then been reformed and given its final name. Under his direction (1929–45), it grew from a small paramilitary formation to one of the most powerful organizations in Nazi Germany. From 1929 until the regime's collapse in 1945, the SS was the foremost agency of security, surveillance, and terror within Germany and German-occupied Europe.
Document 7: Heinrich Müller (Gestapo): Heinrich Müller (28 April 1900; date of death unknown, but evidence points to May 1945) was a German police official under both the Weimar Republic and Nazi Germany. He became chief of the Gestapo, the political secret state police of Nazi Germany, and was involved in the planning and execution of the Holocaust. He was known as "Gestapo Müller" to distinguish him from another SS general also named Heinrich Müller. He was last seen in the "Führerbunker" in Berlin on 1 May 1945 and remains the most senior figure of the Nazi regime who was never captured or confirmed to have died.
Document 8: Reinhard Heydrich: Reinhard Tristan Eugen Heydrich (] ) (7 March 1904 – 4 June 1942) was a high-ranking German Nazi official during World War II, and a main architect of the Holocaust. He was an SS-"Obergruppenführer und General der Polizei" (Senior Group Leader and General of Police) as well as chief of the Reich Main Security Office (including the Gestapo, Kripo, and SD). He was also "Stellvertretender Reichsprotektor" (Deputy/Acting Reich-Protector) of Bohemia and Moravia. Heydrich served as president of the International Criminal Police Commission (ICPC; later known as Interpol) and chaired the January 1942 Wannsee Conference, which formalised plans for the Final Solution to the Jewish Question—the deportation and genocide of all Jews in German-occupied Europe.
Document 9: Eugen Schwitzgebel: Eugen Schwitzgebel (1900 – 31 October 1944, in Aarhus) was a German officer, a SS Sturmbannführer and Gestapo leader in Aarhus during the Second World War. He was described as "short, stocky Bavarian" who was a "ruthless and impatient man who loved to terroize his subordinates". He was killed when British airmen bombed the University of Aarhus building which was being used as the Gestapo headquarters and place for keeping the Danish archives.
Document 10: Klaus Barbie: Nikolaus "Klaus" Barbie (26 October 1913 – 23 September 1991) was an SS and Gestapo functionary during the Nazi era. He was known as the "Butcher of Lyon" for having personally tortured French prisoners of the Gestapo while stationed in Lyon, France. After the war, United States intelligence services employed him for their anti-Marxist efforts, and also helped him escape to South America.
Document 11: Stasi: The Ministry for State Security (German: "Ministerium für Staatssicherheit" , MfS) or State Security Service ("Staatssicherheitsdienst", SSD), commonly known as the Stasi (] ), was the official state security service of the German Democratic Republic (East Germany). It has been described as one of the most effective and repressive intelligence and secret police agencies to have ever existed. The Stasi was headquartered in East Berlin, with an extensive complex in Berlin-Lichtenberg and several smaller facilities throughout the city. The Stasi motto was ""Schild und Schwert der Partei"" (Shield and Sword of the Party), referring to the ruling Socialist Unity Party of Germany (German: "Sozialistische Einheitspartei Deutschlands", SED). Erich Mielke was its longest-serving chief, in power for thirty-two of the GDR's forty years of existence.
Document 12: Gustav Laabs: Gustav Laabs (born 20 December 1902-died 12 March 1980) was a German SS commander during the Nazi era. During the Second World War, he worked as a gas van operator at the Chełmno extermination camp in Wartheland. As an operator of a gas van, Laabs was directly involved in and responsible for the genocidal extermination of over 100,000 men, women and children, most of whom were killed on account of being Jewish. After the war, he was tried and convicted for his crimes against humanity. Despite being convicted, Laabs was given the lenient sentence of 15 years (subsequently reduced to 13 years) by a regional court in Landgericht Bonn, Germany. Far from being outliers, such instances of leniency, extended to perpetrators of genocide and crimes against humanity during trials in post-Nazi Germany, constituted the norm, as evidenced by the fact that most of the perpetrators of Nazi war crimes and the Final Solution were not brought to justice. Many former SS officers and Nazis, who were directly responsible for perpetrating genocide and murdering countless innocent people, were contracted to work for US and British intelligence agencies as part of the war against the USSR and Communism (also see Operation Paperclip for more on post-WWII Allied collaboration with Nazis).
Document 13: Gestapo: The Gestapo (] ), abbreviation of Geheime Staatspolizei, or the Secret State Police, was the official secret police of Nazi Germany and German-occupied Europe.
Document 14: Secret police: The term secret police or covert police force refers to intelligence services or police and law enforcement agencies which engage in covert, domestic law enforcement, intelligence, and counter-intelligence operations. The level of oversight with which they are governed varies by country and political system. Secret police organizations are often used by totalitarian states to protect the political power of an individual dictator or an authoritarian political regime by means of systematic engagement in extrajudicial activities. Secret police organisations are often utilised for the purposes of policing the activities of dissidents, and weakening opposition organisations.
Document 15: Pierre Paoli: Pierre-Marie Paoli, also known as Lamote, (1921 - 1946) was a French agent in the Gestapo. The Gestapo (Secret State Police) was the official secret police of Nazi Germany and German-occupied Europe.
ground_truth: Eugen Schwitzgebel