The Devil Next Door is about a Ukrainian man named John Demjanjuk who lives in Cleveland who was noticed by the FBI as being Ivan the Terrible. Ivan the Terrible was one the soldiers stationed in Sobibor and Treblinka who participated in the murder of 850,000 Jews. The documentary is a battle between the prosecutors who are trying to give evidence to show that he is Ivan and the defense trying to say he is just an innocent man.
Here is the Trailer for the Documentary if you are interested. There are five 45 minute long episodes.