A German historian has used artificial intelligence to identify the executioner in one of the most disturbing and notorious photographs of the nazi Holocaust.
Known as ‘The Last Jew in Vinnitsa’, the 1941 photograph shows a Nazi soldier pointing a gun at the head of a man kneeling at the edge of a pit filled with the bodies of victims, while other soldiers stand watching with expressionless faces.
US-based German historian Jürgen Matthäus has now named the executioner as 34-year-old Jakobus Onnen, and has published his findings in the German-language Journal of Historical Studies.
Mobile killing operations
Onnen was not a high-ranking officer but a French, English and gym teacher, born in 1906, who had joined the Nazi party before Hitler came to power in 1933.
He participated in mobile killing operations responsible for the deaths of more than 100,000 civilians in Ukraine, and was killed in combat in 1943.
Matthäus’s investigation also corrected longstanding errors about the photograph itself.
Through careful analysis of the background, comparing it with 19th-century maps, contemporary photography and modern Google Earth imagery, he established that the location was not Vinnitsa at all, but the citadel of Berdychiv, a city 93 miles south-west of Kyiv.
He also identified the unit as Einsatzgruppe C, under the command of Otto Rasch, and pinpointed the date of the massacre as 28 July 1941.
Correspondence destroyed
The breakthrough in naming Onnen came after Matthäus published his preliminary findings and an anonymous reader came forward suggesting the gunman could be his wife’s uncle, writing: “This horrifying image has played a role in our family for decades.”
Onnen’s family had destroyed his wartime correspondence in the 1990s, but photographs survived.
The distant relative provided those images to Matthäus, who then worked with the investigative journalism group Bellingcat to submit them alongside ‘The Last Jew in Vinnitsa’ for comparative AI analysis.
Matthäus described the match as “unusually high in terms of the percentage the algorithm throws out there.”
He was nonetheless careful about the limits of the technology. “This is clearly not the silver bullet – this is one tool among many. The human factor remains key,” he said.
Massacre trophies
Matthäus believes Onnen was posing for a fellow soldier and that such photographs were frequently treated as trophies from civilian massacres. “The reason I think why he is posing there, the way he depicts himself – I think is meant to impress,” he said.
The historian believes the image deserves wider recognition. “I think this image should be just as important as the image of the gate in Auschwitz, because it shows us the hands-on nature, the direct confrontation between killer and person to be killed,” he said.
He added that photographs of this kind, sent home by soldiers, also challenge the claim that ordinary Germans were unaware of the genocide taking place in the east.
Matthäus is now working with Ukrainian colleague Andrii Mahaletskyi to establish the identity of the victim.
