Twins in the experiments describe three days of what must have been psychological examination and three days of laboratory experiments. "Three times a week we were marched to Auschwitz to a big brick building, sort of like a big gymnasium. They would keep us there for about six or eight hours at a time - most of the days. ..... We would have to sit naked in the large room where we first entered, and people in white jackets would observe us and write down notes. They also would study every part of our bodies. They would photograph, measure our heads and arms and bodies, and compare the measurements of one twin to another. The process seemed to go on and on." (Echoes from Auschwitz, Kor).
The next year, 1942, marked the beginning of mass murder on a scale unprecedented in all of human history. In January, fifteen top Nazis led by Reinhard Heydrich, second in command of the SS, convened the Wannsee Conference in Berlin to coordinate plans for the Final Solution. The Jews of Europe would now be rounded up and deported into occupied Poland where new extermination centers were being constructed at Belzec, Sobibor, Treblinka, and Auschwitz-Birkenau.
The biblical term shoah (Hebrew: שׁוֹאָה), meaning "destruction", became the standard Hebrew term for the murder of the European Jews, first used in a pamphlet in 1940, Sho'at Yehudei Polin ("Sho'ah of Polish Jews"), published by the United Aid Committee for the Jews in Poland.[11] On 3 October 1941 the cover of the magazine The American Hebrew used the phrase "before the Holocaust", apparently to refer to the situation in France,[12] and in May 1943 The New York Times, discussing the Bermuda Conference, referred to the "hundreds of thousands of European Jews still surviving the Nazi Holocaust".[13] In 1968 the Library of Congress created a new category, "Holocaust, Jewish (1939–1945)".[14] The term was popularized in the United States by the NBC mini-series Holocaust (1978), about a fictional family of German Jews,[15] and in November 1978 the President's Commission on the Holocaust was established.[16] As non-Jewish groups began to include themselves as Holocaust victims too, many Jews chose to use the terms Shoah or Churban instead.[12][g] The Nazis used the phrase "Final Solution to the Jewish Question" (German: die Endlösung der Judenfrage).[18]
The SS organization also found it could profit financially from the human traffic. Upon arrival in the camps, all belongings were taken from the Jews. Foreign currency, gold, jewels and other valuables were sent to SS Headquarters of the Economic Administration. Wedding rings, eye glasses, shoes, gold fillings, clothing and even hair shorn from women also served to enrich the SS, with the proceeds funneled into secret Reichsbank accounts. Watches, clocks and pens were distributed to soldiers at the Front while clothing was given to German families.
After the June 1941 German invasion of the Soviet Union, SS and police units (acting as mobile killing units) began massive killing operations aimed at entire Jewish communities. By autumn 1941, the SS and police introduced mobile gas vans. These paneled trucks had exhaust pipes reconfigured to pump poisonous carbon monoxide gas into sealed spaces, killing those locked within. They were designed to complement ongoing shooting operations.
Mengele, in distinctive white gloves, supervised the selection of Auschwitz’ incoming prisoners for either torturous labor or immediate extermination, shouting either “Right!” or “Left!” to direct them to their fate. Eager to advance his medical career by publishing “groundbreaking” work, he then began experimenting on live Jewish prisoners. In the guise of medical “treatment,” Mengele injected, or ordered others to inject, thousands of inmates with everything from petrol to chloroform to study the chemicals’ effects. Among other atrocities, he plucked out the eyes of Gypsy corpses to study eye pigmentation, and conducted numerous gruesome studies of twins.

Racial-Morphological Examinations of the Anterior Portion of the Lower Jaw in Four Racial Groups. This dissertation, completed in 1935 and first published in 1937, earned him a PhD in anthropology from Munich University. In this work Mengele sought to demonstrate that there were structural differences in the lower jaws of individuals from different ethnic groups, and that racial distinctions could be made based on these differences.[7][121]

After WWII had ended, photographs of the Holocaust stunned the public. Newspapers in the United States had reported on the oppression of the Jews in Germany during the war. In 1942, many newspapers were writing details of the Holocaust, but these stories were short and were not widely read. In 1943, after sources had confirmed the killings of at least two million Jews in concentration camps across Europe a Gallup poll found that less than half of Americans believed these reports to be true; 28% thought they were “just a rumor”. The reports were unconfirmed and sometimes denied by the United States government.
Cesarani notes that by 1943, as the military position of the German forces deteriorated, the Nazi leadership became more openly explicit about the Final Solution. In March, Goebbels confided to his diary: "On the Jewish question especially, we are in it so deeply that there is no getting out any longer. And that is a good thing. Experience teaches that a movement and a people who have burned their bridges fight with much greater determination and fewer constraints than those that have a chance of retreat."[127]
Before and after the March 1933 Reichstag elections, the Nazis intensified their campaign of violence against opponents.[77] They set up concentration camps for extrajudicial imprisonment.[78] One of the first, at Dachau, opened on 9 March 1933.[79] Initially the camp contained mostly Communists and Social Democrats.[80] Other early prisons were consolidated by mid-1934 into purpose-built camps outside the cities, run exclusively by the SS.[81] The initial purpose of the camps was to serve as a deterrent by terrorizing Germans who did not conform.[82]
Mengele's work also involved carrying out selections, a task that he chose to perform even when he was not assigned to do so, in the hope of finding subjects for his experiments,[33] with a particular interest in locating sets of twins.[34] In contrast to most of the other SS doctors, who viewed selections as one of their most stressful and unpleasant duties, he undertook the task with a flamboyant air, often smiling or whistling a tune.[35][31] He was also one of the SS doctors responsible for supervising the administration of Zyklon B, the cyanide-based pesticide that was used for the mass killings in the Birkenau gas chambers. He served in this capacity at the gas chambers located in crematoria IV and V.[36]