Reputedly, his family were wealthy farmers, his brother and sister were convicted thieves, and his father in law fought against the Bolsheviks in the White Army commanded by Admiral Kolchak.
[4] Early in 1949, he supervised the interrogation of Boris Shimeliovich, a long-standing party member who came under suspicion because of his war time involvement in the Jewish Anti-Fascist Committee.
At his trial, Shimeliovich told the judge: "I received approximately eighty to one hundred blows a day, so altogether I think I was hit about two thousand times.
"[5] In 1950, Ryumin began the interrogation of Professor Yakov Gilyarievich Etinger, an eminent, elderly Jewish cardiologist, who had made critical remarks about the regime to family and friends.
[7] After Etinger had been put through 37 separate interrogations between November 1950 and January 1951, Ryumin was ordered by the Minister of State Security Viktor Semyonovich Abakumov to ease up because medical staff had warned that stress might kill the elderly prisoner.
[8] Ryumin was reprimanded, and fearing worse was to come, wrote to Stalin on 2 July 1951 accusing Abakumov of covering up a plot by Jewish terrorists.
Reputedly the letter was largely written for him by an official named Dmitri Sukhanov, who ran the private office of Georgi Malenkov.
[9] Stalin's reaction was to promote Ryumin to head of the Department for Specially Important Cases, and to dismiss Abakumov, who was arrested.
It has been suggested, for instance by the historian Robert Conquest, that the lengthy trial was ordered by Malenkov to exonerate himself from any involvement in the Doctors' Plot and Ryumin's other activities.