Fedorenko was mobilized into the Soviet Army in June 1941,[1] around the time of the Nazi German Operation Barbarossa.

He escaped the first time, but he was captured three days later by the Germans and transported to Zhytomyr, then Rivne, and finally to Chełm, Poland.

At the Chełm prisoner-of-war camp, German officers from Operation Reinhard recruited 200 to 300 captured Soviet soldiers for military training as auxiliary police in the service of Nazi Germany within General Government.

Fedorenko was one of approximately 5,000 Trawniki men trained as Holocaust executioners by SS-Hauptsturmführer Karl Streibel from Operation Reinhard.

[3] The Hiwi shooters, known in German as the Trawnikimänner, were deployed to all major killing sites of the Final Solution, augmented by the SS and Schupo, as well as Ordnungspolizei formations.

It is known from historical record that between mid-March and mid-April 1942 over 30,000 Jews from Lublin Ghetto were transported to their deaths in cattle trucks at the Bełżec extermination camp and additional 4,000 at Majdanek.

From September 1942 to August 1943,[8] he led a 200-member ex-Soviet soldier detachment which shaved, stripped, beat and gassed prisoners brought to Treblinka.

Fedorenko emigrated to the United States from Hamburg in 1949 and was granted permanent residency status under the Displaced Persons Act.

Treblinka survivors identified him as a guard at the camp from a collection of photographs and documents that had been captured from the SS.

In the mid-1970s, Congressional Representatives Joshua Eilberg and Elizabeth Holtzman initiated a set of hearings that led the US Government Accountability Office (GAO) to investigate the handling of possible Nazi war criminal data.

[14] Fedorenko argued that his service at Treblinka had been involuntary and, since he had worked only as a perimeter guard, he had virtually no contact with the prisoners.

He had mistreated no one and, therefore, when he lied on his immigration forms about his birthplace and wartime service, it was not about any material fact that would have excluded him from entering the US.

"[15] Six Treblinka survivors, however, testified that Fedorenko had in fact committed atrocities, namely beating and shooting Jewish prisoners.

Lastly, Pinchas Epstein said Fedorenko shot and killed a friend of his, after making him crawl naked on all fours.

[21] Allan Ryan then of the Solicitor General's Office presented the appeal before the Fifth Circuit Court on behalf of the INS.

[attribution needed][failed verification] During his trial, Fedorenko's family disowned him, with his sons writing public letters denouncing him.

[28] The prosecutor was adamant that Fedorenko should be executed, while his lawyer asked the court for leniency on the grounds of his client's age.

A subsequent appeal to the Supreme Court of the USSR was rejected, and his execution by firing squad was announced on July 28, 1987.