question: Which Soviet Union dictator did secret police officer Stainslav Redens work for?
answer: Joseph Stalin
context: Title: Chronology of Soviet secret police agencies
  Passage: There was a succession of Soviet secret police agencies over time.  The first secret police after the October Revolution, created by Vladimir Lenin's decree on December 20, 1917, was called "Cheka" (ЧК).  Officers were referred to as "chekists", a name that is still informally applied to people under the Federal Security Service of Russia, the KGB's successor in Russia after the dissolution of the Soviet Union.
  Title: Gulag
  Passage: The Gulag (Russian: ГУЛАГ ; ] ; acronym of Главное Управление Лагерей , "Glavnoye Upravleniye Lagerej ", "Main Camps' Administration" or "Chief Administration of Corrective Labor Camps") was the government agency created under Vladimir Lenin which reached its peak as the Soviet forced labor camp system during Joseph Stalin's rule from the 1930s up until the 1950s.  The term is also commonly used to reference any forced-labor camp in the Soviet Union, including in post-Stalin times.  The camps housed a wide range of convicts, from petty criminals to political prisoners. Large numbers were convicted by simplified procedures, such as NKVD troikas (secret police) and other instruments of extrajudicial punishment.  The Gulag is recognized as a major instrument of political repression in the Soviet Union.
  Title: Joseph Stalin
  Passage: Joseph Vissarionovich Stalin (18 December 1878 – 5 March 1953) was a Georgian-born Soviet revolutionary and political leader.  Governing the Soviet Union as its dictator from the mid-1920s until his death in 1953, he served as General Secretary of the Central Committee of the Communist Party of the Soviet Union from 1922 to 1952 and as Premier of the Soviet Union from 1941 to 1953.  Ideologically a Marxist and a Leninist, Stalin helped to formalise these ideas as Marxism–Leninism while his own policies became known as Stalinism.
  Title: KGB
  Passage: The KGB, an initialism for Komitet Gosudarstvennoy Bezopasnosti (Russian: "Комите́т Госуда́рственной Безопа́сности" ("КГБ") ; ] ), translated in English as Committee for State Security, was the main security agency for the Soviet Union from 1954 until its break-up in 1991, as a direct successor of such preceding agencies as Cheka, NKGB, NKVD and MGB, a committee was attached to the Council of Ministers.  It was the chief government agency of "union-republican jurisdiction", acting as internal security, intelligence and secret police.  Similar agencies were constituted in each of the republics of the Soviet Union aside from Russia, and consisted of many ministries, state committees and state commissions.
  Title: OVRA
  Passage: The Organizzazione per la Vigilanza e la Repressione dell'Antifascismo (OVRA; Italian for "Organization for Vigilance and Repression of Anti-Fascism") was the secret police of the Kingdom of Italy, founded in 1927 under the regime of Fascist dictator Benito Mussolini and during the reign of King Victor Emmanuel III.  The German Gestapo were the equivalent of the OVRA.  Mussolini's secret police were assigned to stop any anti-Fascist activity or sentiment.  Approximately 5,000 OVRA agents infiltrated most aspects of domestic life in Italy.  The OVRA was headed by Arturo Bocchini.
  Title: Stanislav Redens
  Passage: Stanislav Frantsevich Redens (Russian: Станислав Францевич Реденс , Polish: "Stanisław Redens" ; May 17, 1892 – January 21, 1940) was a Soviet secret police official, one of those responsible for conducting mass repressions under Joseph Stalin.  Redens was himself executed in 1940, after being arrested at the end of the Great Purge in 1938.
  Title: State Protection Authority
  Passage: The State Protection Authority (Hungarian: "Államvédelmi Hatóság" or "ÁVH") was the secret police of Hungary from 1945 until 1956.  It was conceived as an external appendage of the Soviet Union's secret police forces and gained an indigenous reputation for brutality during a series of purges beginning in 1948, intensifying in 1949 and ending in 1953.  In 1953 Joseph Stalin died, and Imre Nagy (a moderate reformer) was appointed Prime Minister of Hungary.  Under Nagy's first government from 1953 to 1955, the ÁVH was gradually reined in.
citations: Joseph Stalin Stanislav Redens