Jakob (Jack) Reimer (November 6, 1918 – August 3, 2005) was a Trawniki camp guard who later emigrated to the United States and became a salesman and restaurant manager. Born to German Mennonite parents in Friedensdorf (now Khmelnytskyi), Ukraine, Reimer studied to be a librarian before being drafted into the Soviet Army in 1940. When Germany invaded the Soviet Union on June 22, 1941, Reimer entered combat and was captured by German forces on July 6. Two months later, he was transferred to the Trawniki concentration camp where he was trained as a camp guard. While serving as a camp guard, Reimer participated in the liquidation of Jewish ghettos in Poland, in addition to administrative and office duties. On one occasion, Reimer fired a shot over a pit containing corpses and at least one live civilian, which would later prove pivotal in his denaturalization trial. In 1944, he received a War Meritorious Medal for his service, and was promoted to Guard First Sergeant in 1945. In 1944, Reimer gained German citizenship after Adolf Hitler made all ethnic German military and police personnel eligible for German citizenship. He later applied for a visa to the United States in 1952 and was naturalized as a United States citizen on April 28, 1959. During his time in the United States, he worked as a Wise potato chip salesman and a restaurant manager, and lived in Brooklyn, New York. After he retired, he moved to Carmel, New York, and was living in Fort Lee, New Jersey at the time of his death. Reimer was first investigated by American authorities in 1980 in connection with the John Demjanjuk case, but little progress was made during this initial investigation. Not until 1992, after the fall of the Soviet Union, did investigators make substantial progress. That year, the Office of Special Investigations filed a denaturalization suit against Reimer, and following a bench trial in 1998, Reimer was denaturalized on September 5, 2002. He appealed his denaturalization, but the United States Court of Appeals for the Second Circuit upheld it on January 27, 2004. In 2005, the government sought to deport Reimer, and he agreed to leave for Germany, but he died before his deportation could be completed.