From August 1942 to August 1943, the German extermination camp of Treblinka (Poland) employed the services of a Ukrainian whose exceptional brutality and huge stature earned him the nickname of Ivan Grozny – Ivan the Terrible. He operated the diesel engines by which the gas for the gas chambers was produced. Ivan was implicated in the murder of 850,000 Jews.

More than thirty years later, in 1975, suspicion fell for the first time on one John Demjanjuk, a worker in the Ford plant in Cleveland, Ohio. He was of Ukrainian descent and had been living in the United States since 1951. He owed his job to his mechanical skills. The name of Demjanjuk appeared on German documents confiscated by the Red Army at the end of the war, which the Soviet authorities had forwarded to several American senators. American law does not provide for the prosecution for war crimes committed in other countries. However, if it can be proved that a person lied during the immigration proceedings he can be stripped of his United States citizenship. From 1947 to 1951, Demjanjuk had been kept in a German camp for stateless persons, where he had been interrogated by members of the US immigration service about, among other things, his activities during the war. Demjanjuk had told them that from 1937 to 1943 he had been ‘a farm worker in a Polish hamlet called Sobibor’.