Jakobus Onnen

Jakobus Onnen (3 August 1906 – 12 August 1943) was a German schoolteacher and a member of the Nazi Schutzstaffel (SS) who served in a mobile killing unit during World War II. He was identified as the individual who appears as the executioner in the Holocaust photograph The Last Jew in Vinnitsa, which depicts a Nazi officer about to shoot a Jewish man at a mass grave in 1941, by the historian Jürgen Matthäus in 2025. Onnen was killed in action on the Eastern Front in 1943 and was never prosecuted for his crimes, remaining unidentified as a war criminal for decades after the war. near the Dutch border. After attending the local primary school for four years, he went to the Latin school in Weener in 1917, after which, from 1921, he attended the Realgymnasium for Boys in Leer, Lower Saxony, graduating in 1927. From October 1934 to March 1936, Onnen was engaged in preparatory service for the assessor exam in Heiligenstadt, which was a requirement for his employment in the German Colonial School in Witzenhausen, Hesse. However, according to a May 1939 report on the German Colonial School, his performance as a teacher was subpar: "The teaching staff suffers in both their reputation and their performance because immoral and conscienceless individuals like a teacher Onnen ... are allowed to act. Apart from his inability to master the languages he claims to teach, there are drinking parties and fraternizing with students".

Memorial in front of the Rheiderland local history museum. Onnen's name is listed on the plaque at the very bottom right.

Onnen took part in these atrocities as a low-ranking SS member. By July 1941 he had already committed his first murders as part of Einsatzgruppe C's killing operations. According to Matthäus, participating in mass shootings did not advance one's career in such units: "The participation in such massacres brought neither career nor rewards, in these killing units it was considered normal".

Onnen continued to serve with Nazi security forces through 1942, during which Einsatzgruppe C and affiliated units carried out mass murder across occupied Soviet territories. On 12 August 1943, Onnen, at the age of 37, was killed in combat near Korosten in Zhitomir Oblast, in western Ukraine, and was buried at a military cemetery in Kiev . In his hometown region of Weener, his name was inscribed on a local war memorial honoring those victimized by war. After Matthäus published his research the council began considerations to remove his name from the memorial, with the conclusion being that his name would be covered by a plaque with a QR code, through which visitors could find out about him.