Over 60 years after the end of World War II, this may be Germany's last big war crimes trial.
But the BBC's Oana Lungescu in Munich says that, as the first to focus on a low-ranking foreigner rather than a senior Nazi commander, it breaks new legal ground.
Defence lawyer Ulrich Busch said it should never have gone to trial.
"How can you say that those who gave the orders were innocent... and the one who received the orders is guilty?" Mr Busch told the court.
"There is a moral and legal double standard being applied today."
Mr Busch has said even if it could be proved his client — who was captured by the Nazis while fighting in the Soviet army — was in Sobibor [a death camp in Poland], he would have been there under duress.
Demjanjuk, you may recall, has been tried before, in Israel. In its new issue, Esquire reviews the evidence against him and finds it as suspect as the motivations for trying him again, in Germany:
"The whole world is going to be looking," [prosecutor Hans-Joachim] Lutz says, and this undoubtedly is true, because if there is a global cultural evergreen, it is Nazi Germany, where pornographic violence and unbounded hate were not only official state policy but dressed in shiny leather. Who can turn away?
But guilt and innocence, not to mention truth and justice, are beside the point in this case. The Germans did not bring Demjanjuk here to determine his guilt, but to assuage their own. Regardless of the verdict, the old man's fate will be the same: Demjanjuk they brought here to die.