WachmännerNikolay Yegorovich Shalayev (Ukrainian language:Микола Єгорович Шалаєв
) was an SS auxiliary guard (Hilfswilligen) trained at Trawniki and serving at the Treblinka extermination camp in occupied Poland during the Holocaust. He was one of two Ukrainian guards (along with Ivan Marchenko) in charge of the motor that produced the exhaust fumes which were fed into the gas chambers during the killing process. He was tried in the Soviet Union and sentenced to death in 1951 for treason. On 3 May 1951 he gave testimony to his KGB interrogators about the gassing at Treblinka. In an attempt to defuse the sheer enormity of his crimes he kept pointing his finger at the Jews from the Sonderkommando "helping him". Both Shalayev and Marczenko (known to his victims from Treblinka as "Ivan the Terrible") were sent by the SS to Trieste, Italy, where they worked killing prisoners at the Risiera di San Sabbaconcentration camp before the war's end.