The Ukrainian refugee arrived in Cleveland after World War II with his wife and daughter. He changed his name from Ivan to John, became a U.S. citizen, and lived a quiet, law-abiding life. But decades later, the past would come back to haunt John Demjanjuk. Prosecutors in Israel and Germany accused him of volunteering as a guard at Nazi death camps and willingly participating in the killing of Jews. Demjanjuk insisted that he was the victim of mistaken identity, and that he had spent most of the war as a prisoner in Germany and Poland. At the time of his death, Demjanjuk was still protesting his innocence.

Demjanjuk was born to a destitute peasant family in central Ukraine, said the London Telegraph. He was called up by the Soviet army in late 1940 and captured two years later by the Germans. “The question of what happened next would come to dominate the rest of his life.” Demjanjuk said he was eventually forced to join Germany’s Vlasov army, an anti-communist force made up of Soviet prisoners. At war’s end, he spent six years in a camp for displaced persons before immigrating to the U.S. in 1952.

In 1986, he was extradited to Israel for the first war-crimes trial since the prosecution of Adolf Eichmann a quarter-century earlier, said The Washington Post. Witnesses and prosecutors said he was “Ivan the Terrible,” a sadistic gas-chamber operator at the Treblinka extermination camp in Poland, where more than 800,000 prisoners were killed. Demjanjuk was convicted of genocide in 1988 and sentenced to hang. But five years later, the Israeli Supreme Court overturned the conviction after new evidence emerged that another Ukrainian, not Demjanjuk, was probably that Ivan.

On returning to the U.S., Demjanjuk received a hero’s welcome from fellow Ukrainian expatriates. But in 2009 he was deported to Germany on charges that he had served as a guard at the Sobibor camp in Poland, and helped kill almost 30,000 Jews. No living witnesses placed him there, in a case “largely based on documentary evidence,” said The New York Times, including a Nazi order showing that Demjanjuk was posted to Sobibor. Demjanjuk was found guilty and sentenced to five years in prison; his appeal was pending when he died in a nursing home.