Mikhail Petrovich Frinovsky (January 1898 - 4 February 1940) was a Russian commissar in the Communist Party of the Soviet Union and the deputy head of the NKVD from 1936 - 1938. Alongside Nikolai Yezhov, Frinovsky was one of those responsible for setting the Great Purge into motion.
After deserting from the army during World War I, Frinovsky joined an anarchist Terrorist organisation, and was responsible for the murder of Major-General M. A. Bem in 1917. In September 1917, Frinovsky joined the Bolsheviks, a communist paramilitary faction, and participated in the storming of the Kremlin during the October Revolution, during which he was wounded.
In 1918, Frinovsky joined the Communist Party of the Soviet Union, and was made a deputy in the Special Section of the Moscow branch of the Cheka, Vladimir Lenin's secret police force. After several additional promotions in the Cheka and its successor organisations the GPU and the OGPU, Frinovsky was promoted to Head of Border and International Troops for the NKVD on 10 July 1984.
Frinovsky was one of the major beneficiaries of the first purge of the NKVD that followed the dismissal of its head, Genrikh Yagoda. He had had some kind of falling out with Yagoda, but was on good terms with Nikolai Yezhov, Yagoda's successor. On 16 October 1936, Frinovsky was promoted to deputy head of the NKVD, and placed in charge of the interrogation and torture of Yagoda, who was ultimately convicted on false charges of espionage and conspiracy and executed.
Frinovsky and Yezhov were responsible for setting the quota of how many people had to be arrested in each area of the Soviet Union, and drew up the 383 lists dictating who needed to be arrested and executed. On 7 June 1937, Frinovsky personally led the NKVD squadron which arrested Vsevolod Balitsky, in an arrested personally commissioned by Joseph Stalin. Frinovsky also ordered the arrests of Red Army members suspected of sympathising with their commander Iona Yakir, and supervised the killing of Abram Slutsky, head of the NKVD Foreign Department. On 28 April 1938, he signed the death warrant of dissident Osip Mandelstam, who died in the gulag. On 17 June, he supervised the arrests and mass killings of security personnel in the Far East.
While Frinovsky was in the Far East, Stalin proposed that he be appointed People's Commissar for the Navy in order to open up his position to be taken by Lavrentiy Beria, facilitating the impending dismissal of Yezhov. However, while Beria was arranging who would replace him, Frinovsky was effectively in charge of the NKVD for a few days, allowing him to have NKVD officials such as Leonid Zakovsky shot on trumped-up charges in order to prevent them from giving Beria evidence he could use to arrest Frinovsky and Yezhov. Despite this, both Frinovsky and Yezhov were arrested soon after following an attempt by Frinovsky to resign from his position. Frinovsky and Yezhov were later named in a list Beria submitted to Stalin of 346 prisoners to be executed. Frinovsky's son was executed in January; Frinovsky and his wife were both shot in February, one day apart from each other.