The Nazi murderer in a 1941 photograph titled ‘The Last Jew in Vinnitsa’ was finally identified with the help of artificial intelligence and a historical researcher, according to a new publication in September.
Published in the Journal of Historical Studies, researcher Dr. Jürgen Matthäus identified the Nazi as 34-year-old Jakobus Onnen, a teacher from the town of Tichelwarf.
A retired teacher contacted Matthäus to tell him he believed Onnen was the uncle of his wife. “This horrifying image has played a role in our family for decades,” the anonymous educator wrote.
Photos were taken of the Holocaust as “trophy items,” Matthäus said. “It’s like pornography, you show it around.”
Onnen’s living relatives provided Matthäus with photos of him, which AI confirmed was a 99.9% match with the photo of the Nazi killer.
"This is a massive step forward in getting to the historical reality of the Holocaust. These are the moments where - if I can generalize - where historians are really thinking, 'Aha, here I've really pushed the limit of what we know,'" Matthäus told DW.
Onnen died in 1943, without facing trial for his crimes. It is believed he was killed by Soviet partisans. Nothing is known of the fate of the living Jew in the photo nor of the photographer.
Onnen was born to a middle-class family, and his father was an educator. His father’s death in 1924 became a “crucial event” that led to Onnen eventually joining the Nazi Party in 1931. The teacher went on to become a member of the SS in 1932.
While working in the SS, Onnen also took up teaching languages and physical education at the Witzenhausen Colonial School.
Shortly before the Nazi invasion of Poland began, Onnen took up employment in the SS Death’s Head Unit at the Dachau concentration camp and later served as a training officer in Poland before joining Einsatzgruppe C in 1941.
"He joined the SA and then later the SS. His study time in Göttingen was clearly influenced by the Nazi student movement, which was very strong, particularly in Göttingen at the time. So here is the Nazification that you can observe," said Matthäus.
The Last Jew in Vinnitsa
The 1941 picture had originally come to public attention 20 years after it was taken, during the trial of Adolf Eichmann in Jerusalem.
Holocaust survivor Al Moss had come into possession of the photo in 1945 and had shared it so people would “know what went on in Eichmann’s time.”
The photo was initially believed to have been taken in Vinnitsa, a Ukrainian town formerly part of the Soviet Union, though Matthäus concluded in 2024 that the photo was likely taken 50 miles north in Berdichev.
Matthäus’s conclusion came after the discovery of a similar photo pressed in the pages of a diary written by an Austrian soldier. The photo was labeled as having been taken at Berdichev’s citadel on July 28, 1941.
The massacre had been carried out by the Einsatzgruppen death squads, a group formed by the SS chief Heinrich Himmler, during the advance toward St. Petersburg. As Nazi soldiers proceeded toward Wehrmacht, they rounded up and massacred Jews throughout the Soviet countryside.