These photos were taken between May and December 1944, and they show the officers and guards of the Auschwitz relaxing and enjoying themselves — as countless people were being murdered and cremated at the nearby death camp. In some of the photos, SS officers can be seen singing. In others they are hunting and in another a man can be seen decorating a Christmas tree in what could only be described as a holiday in hell. The album also contains eight photos of Josef Mengele — some of the very few existing snapshots taken of the concentration camp’s notorious doctor during the time he spent there.

The images are significant because there are few photos available today of the “social life” of the SS officers who were responsible for the mass murder at Auschwitz. These are the first leisure time photos of the concentration camp’s SS officers to be discovered, though similar images do exist for other camps, including Sachsenhausen, Dachau and Buchenwald.

The album belonged to Karl Höcker, the adjutant to the final camp commandant at Auschwitz, Richard Baer. Höcker took the pictures as personal keepsakes. Prior to its liberation by the Allies, Höcker fled Auschwitz. After the war, he worked for years, unrecognized, in a bank. But in 1963 he was forced to answer to charges for his role at Auschwitz at a trial in Frankfurt. In his closing words in the trial, Höcker claimed: “I had no possibility in any way to influence the events and I neither wanted them to happen nor took part in them. I didn’t harm anyone and no one died at Auschwitz because of me”. In the end, though, he was convicted on charges of aiding and abetting the murders of 1,000 Jews and was sentenced to seven years in prison. He was released after serving five years. In 2000, he died at the age of 88.

The photos were made public by the United States National Holocaust Museum in Washington. The museum obtained the photos from a retired US Army intelligence officer, who came across the album in an apartment in Frankfurt and has now given them to the museum. “These unique photographs vividly illustrate the contented world they enjoyed while overseeing a world of unimaginable suffering”, museum director Sara Bloomfield said in a statement. “They offer an important perspective on the psychology of those perpetrating genocide”. The director of the museum’s photographic reference collection, Judith Cohen, said there are no photos depicting anything abhorrent, “and that’s precisely what makes them so horrible”.

A few of the published photos of Karl Hoecker’s album known as “Laughing at Auschwitz”:

Later in this series of photographs, “the women and the officer turn their bowls to the camera; some invert them to show that they are empty,” Wilkinson writes. “One woman pretends to weep. The scene took place on July 22, 1944. On July 23rd the Soviets liberated Majdanek, the first concentration camp to fall. Majdanek was about a hundred and eighty miles northeast of Auschwitz. When the camp was abandoned, a thousand prisoners were force-marched to Auschwitz. Only half of them arrived.

“In a series of photographs, the women and three officers run toward the camera, grinning wildly, apparently because it has suddenly begun to rain,” Wilkinson writes.

The women with Hoecker “were typists, telegraph clerks, and secretaries in Auschwitz, and were called Helferinnen, which means ‘helpers,’” Wilkinson writes. “Their racial purity had been established—should an officer be looking for a girlfriend or a wife, the Helferinnen were intended to be a resource.”

Camp commandant Richard Baer, notorious concentration camp doctor Josef Mengele (The Angel of the Death), and the commandant of the Birkenau camp, Josef Kramer (obscured) and former commandant Rudolf Höss.

As the SS members took time off, hundreds were being exterminated nearby at Auschwitz.

This photograph, taken at Auschwitz, shows “nearly a hundred officers arrayed like a glee club up the side of a hill. The accordion player stands across the road,” Wilkinson writes. “All the men are singing except those in the very front, who perhaps feel too important for it.” The group includes Richard Baer; Rudolf Hoess, who had supervised the building of Auschwitz and had been its first commandant; and Josef Mengele, the doctor who performed infamous medical experiments on twins and other prisoners. This album contains eight pictures of Mengele—the only known photographs of him at Auschwitz.

“Hoecker was born in Engerhausen, Germany, in December, 1911, the youngest child of six. His father, a bricklayer, died in the First World War, leaving his family impoverished. Hoecker worked at a bank, then joined the SS in 1933. At the beginning of the war, he was drafted into the SS Fighting Corps, and in 1940 he was sent to work at Neuengamme concentration camp, near Hamburg. In 1942, he was transferred to Majdanek, where he was adjutant during the Harvest Festival of November, 1943, when all the Jews from three camps, including Majdanek, were assembled and shot, in order to prevent uprisings. Forty-two thousand prisoners were killed in two days”.

“Rudolf Hoess, in ‘Death Dealer,’ a memoir he wrote after his arrest, noted that the adjutant ‘has a special position of trust. He must insure that no important event in the camp remains unknown to the Commandant”, Wilkinson writes. “A few days before Soviet troops liberated Auschwitz, in January, 1945, Hoecker and Baer fled to Germany, where Baer was made commandant of the Dora-Mittelbau camp, and Hoecker was again his adjutant. When that camp was liberated by American troops, in April, Hoecker and Baer followed the advice of Heinrich Himmler, the head of the SS, which was that SS officers insinuate themselves among the troops, in the hope of being taken for ordinary soldiers. Hoecker joined a fighting unit that was captured by the British in northern Germany. He spent a year and a half in a POW camp, and was released, apparently because no one recognized him”.

The “small, chubby, bald man wearing a suit”, Wilkinson writes, “is Carl Clauberg, a doctor who performed sterilization experiments on women, using acid. He was tried by the Soviets, in 1948, and sentenced to twenty-five years in prison. He was released early and arrested again, by the Germans; he died in 1957, awaiting his second trial”.

Hoecker in his summer uniform — “a little wilted, his sleeves rolled”, Wilkinson writes. After the war, Hoecker went back to his bank job. But “in 1952, he turned himself in for having belonged to the SS”, Wilkinson writes. He was sentenced to nine months that he never served. Hoecker was tried again in 1963 at the Frankfurt Auschwitz trials, found guilty of “aiding and abetting the death of a thousand people on four occasions,” and received a seven-year sentence—but escaped more serious charges because he insisted that he had never been on the selection ramp where prisoners were divided between work duty and the gas chambers. He served part of his sentence, “was paroled in 1970, returned again to his job at the bank, and died, at eighty-nine, in 2000”.