I'm currently reading Rodric Braithwaite's excellent Moscow 1941, an account of the German invasion of the Soviet Union with a focus of the life of the city itself.
Russia had been in the grips of the Terror since the start of the big purges in 1937:
In the four years before the war more than thirty-two thousand people died at the hands of the secret police in Moscow and the surrounding Region.
Two corpse disposal zones had been set up outside the city, one at Butovo, the other at Kommunarka. Most of the elite, including artists and writers, were killed at the NKVD dacha at Kommunarka. And it's here that I learned of a figure I had not heard of before, but about whom I intend to learn more, Vasili Blokhin:
Many of these executions were carried out by a squad under the command of Vasili Blokhin, a specialist in such matters. Blokhin is said to have personally killed the theatre director Meyerhold, the writer Isaak Babel and Mikhail Koltsov, the journalist and hero of the Spanish Civil War.
Blokhin also took a key role in the 1940 Katyn Massacre of the Polish officer corps, "wearing a leather apron and cap and long leather gloves": he apparently carried out many of the killings of the Polish POWs personally, with a German Walther pistol he favored because it didn't jam when hot, at Mednoe, north of Moscow.
How is it that Blokhin is not better known? The winnowing of writers in those years was brutal: first silenced, then tortured and killed. And if Blokhin did indeed carry out the killings personally, he was probably the last person to see them before they died. Whether they saw him, I don't know.