BERLIN (AP) — John Demjanjuk, a retired U.S. autoworker who was convicted of being a guard at the Nazis' Sobibor death camp despite steadfastly maintaining over three decades of legal battles that he had been mistaken for someone else, died Saturday, his son told The Associated Press. He was 91.Demjanjuk, convicted in May of 28,060 counts of being an accessory to murder and sentenced to five years in prison, died a free man in a nursing home in the southern Bavarian town of Bad Feilnbach.