He was engaged in investigating the crimes of the Nazis in the occupied territories of the Soviet Union.

Participated in the work of the Nuremberg International Military Tribunal as an assistant to the chief prosecutor from the Soviet Union, Roman Rudenko.

Supported the charges section by section: In 1946, he was Deputy Prosecutor from the Soviet Union of Prosecutor Sergei Golunsky at the Tokyo International Trial on charges of the main Japanese war criminals (military aggression in the areas of Lake Khasan and the Khalkhin Gol River).

In 1962–1972 – Chairman of the Supreme Court of the Russian Soviet Federative Socialist Republic.

He was a member of the International Commission of Inquiry to Expose the Atrocities of American Imperialism in Vietnam, a member of the United Nations Standing Advisory Committee of Experts on the Prevention of Crime and the Treatment of Criminals, a member of the Council of the International Organization of Democratic Lawyers, and an honorary doctorate in law from a number of foreign universities.