Although the composition of the ground, largely sand, was favorable for ground-penetrating radar, the dense forest surrounding the site interfered enough with the radar signals that they decided to try another tack. Paul Bauman and Alastair McClymont, geophysicists with Advisian WorleyParsons, a transnational engineering company, had more luck with electrical resistivity tomography, or ERT, which was originally developed to explore water tables and potential mining sites. ERT technology sends jolts of electrical current into the earth by way of metal electrodes hooked up to a powerful battery and measures the distinctive levels of resistivity of different types of earth; the result is a detailed map to a depth of more than a hundred feet.
The hero, or irritant (depending on which side of the controversy one favors), in the genesis of the diary’s dramatization was Meyer Levin, a Chicago-born novelist of the social-realist school, the author of such fairly successful works as “The Old Bunch,” “Compulsion,” and “The Settlers.” Levin began as a man of the left, though a strong anti-Stalinist: he was drawn to proletarian fiction (“Citizens,” about steelworkers), and had gone to Spain in the thirties to report on the Civil War. In 1945, as a war correspondent attached to the Fourth Armored Division, he was among the first Americans to enter Buchenwald, Dachau, and Bergen-Belsen. What he saw there was ungraspable and unendurable. “As I groped in the first weeks, beginning to apprehend the monstrous shape of the story I would have to tell,” he wrote, “I knew already that I would never penetrate its heart of bile, for the magnitude of this horror seemed beyond human register.” The truest telling, he affirmed, would have to rise up out of the mouth of a victim.
In early 1943, encouraged by von Verschuer, Mengele applied to transfer to the concentration camp service.[20][30] His application was accepted and he was posted to Auschwitz, where he was appointed by SS-Standortarzt Eduard Wirths, chief medical officer at Auschwitz, to the position of chief physician of the Zigeunerfamilienlager (Romani family camp) at Birkenau,[20][30] a subcamp located on the main Auschwitz complex. The SS doctors did not administer treatment to the Auschwitz inmates, but supervised the activities of inmate doctors who had been forced to work in the camp medical service.[31] As part of his duties, Mengele made weekly visits to the hospital barracks and ordered any prisoners who had not recovered after two weeks in bed to be sent to the gas chambers.[32]
Zeidel had spent the previous two years in German-occupied Vilnius, in the city’s walled-off Jewish ghetto. He’d watched as the Nazis sent first hundreds and then thousands of Jews by train or truck or on foot to a camp in the forest. A small number of people managed to flee the camp, and they returned with tales of what they’d seen: rows of men and women machine-gunned down at close range. Mothers pleading for the lives of their children. Deep earthen pits piled high with corpses. And a name: Ponar.

From the Kristallnacht pogrom onwards, Nazi policy toward the Jews radicalized relentlessly, reaching deliberate continental genocide of a kind never before seen in history by 1941-1942. It is here, however, that considerable difference of opinion among historians begins. Over the past twenty years or so, a consensus has emerged that Hitler did not embark on his campaign of killing all Jews in the Soviet Union, including women and children, immediately after the invasion began in June 1941, but only several months later. At first, it seems, only adult male Jews and “commissars” (Soviet state operatives) were killed; one of the best-known recent expositions of this viewpoint is Philippe Burrin’s 1994 Hitler and the Jews: The Genesis of the Holocaust . Nearly all of the detailed documentation of the Holocaust, including recently discovered records, points to this conclusion. Nonetheless, by the end of 1941, Nazi killing squads ( Einsatzgruppen ) had killed hundreds of thousands of Jews in the western Soviet Union, murdering men, women, and children indiscriminately. Beginning in early 1942, the extermination camps (all located in conquered Poland) began to murder Jews, and others, brought in from all parts of Europe.
Mengele earned his first doctorate in anthropology from the University of Munich in 1935. He did his post-doctoral work at Frankfurt under Dr. Otmar Freiherr von Verschuer, who was a fully indoctrinated Nazi eugenicist. National Socialism always held that individuals were the product of their heredity, and von Verschuer was one of the Nazi-aligned scientists whose work seemed to legitimize that assertion.
Mengele was born on 16 March 1911 to Walburga (née Hupfauer) and Karl Mengele in Günzburg, Bavaria, Germany.[4] He was the oldest of three children; his two younger brothers were Karl Jr. and Alois. Their father was founder of the Karl Mengele & Sons company, producers of farm machinery.[5] Josef was successful at school and developed an interest in music, art, and skiing.[6] He completed high school in April 1930 and went on to study philosophy in Munich,[7] where the headquarters of the Nazi Party were located.[8] In 1931, Mengele joined the Stahlhelm, Bund der Frontsoldaten, a paramilitary organization that was absorbed into the Nazi Sturmabteilung (Storm Detachment; SA) in 1934.[7][9]