Nitpick: The FBI confirmed that according to their opinion one piece of evidence was a fake.
Throughout three decades of US hearings, an extradition, a death sentence followed by acquittal in Israel, a deportation and now a trial in Munich, the arguments have relied heavily on the photo ID from an SS training camp that indicates Demjanjuk was sent to Sobibor.
Claims that the card and other evidence against Demjanjuk are Soviet forgeries have repeatedly been made by Demjanjuk's defense attorneys. However, the FBI report provides the first known confirmation that American investigators had similar doubts.
Where did the FBI confirm his innocence?
In 2011 the Associated Press had uncovered a secret 1985 FBI report which indicated that a Nazi ID card showing that Demjanjuk had served as a death camp guard was a Soviet-made fake.
He survived the ordeal, and volunteered to be sent to the Trawniki concentration camp division utilized for the training Hiwi guards recruited from Soviet POWs
http://www.nola.com/crime/index.ssf/2011/04/fbi_secret_repor...
https://www.google.com/search?q=FBI+thought+Demjanjuk+eviden...
[1] https://en.wikipedia.org/wiki/John_Demjanjuk