I'd forgotten a lot about this case but recently watched a documentary on it and refreshed it all. He was being railroaded for being "Ivan the Terrible", the worst of the worst. A sadist who mutilated people with a sword before pushing them into a gas chamber while laughing. There wasn't much real info on Ivan the Terrible, just legends and stories. There was no hard evidence really except one ID card and photo that showed a trainee who resembled Demjanjuk and had the name Ivan instead of John at a different camp, and a bunch of 80 year olds who said they recognize him from 45 years prior (one of whom said he'd taken a train from Germany to Miami to meet with US officials and identify Demjanjuk). I remember this time and there were a lot of people who thought he wasn't getting treated fairly. And in fact, he'd absolutely have been convicted of being Ivan the Terrible if the soviet union hadn't fallen and archival info there proved beyond much doubt that he just plain wasn't. They had actual photos and descriptions of Ivan taken from the camps directly and he was a short guy with dark hair and definitely not Demjanjuk who was tall and blonde. Oops.
But there was a second trial and he was convicted of being a guard at a different camp, not the worst monster of the whole thing. Based on the evidence and his own shaky story, that seems right.