A German court has found John Demjanjuk guilty of helping to murder Jews at a Nazi death camp in World War II.
He was sentenced to five years in prison, one year less than prosecutors had asked for.
Prosecutors said the Ukraine-born Demjanjuk, 91, was a guard at Sobibor camp in Poland in 1943.
Demjanjuk denied serving as a guard, saying that as a Soviet prisoner of war of the Nazis, he was a victim too.
Lawyers for Demjanjuk have said they will appeal the conviction.
It is not clear whether Demjanjuk, whose family says he is very ill, will get credit for time already served.
He has been in custody since being extradited from the US in 2009.
After the war Demjanjuk lived in the US, where he worked in an Ohio car factory, and became an American citizen.
Born in Ukraine in 1920, Demjanjuk grew up under Soviet rule.
He was a soldier in the Red Army in 1942 when he was captured by the Germans.
Prosecutors had argued he was recruited by the Germans to be an SS camp guard and that by working at a death camp he was a participant in the killings.
It was the first time such a legal argument was made in a German court.
"The court is convinced that the defendant... served as a guard at Sobibor from 27 March 1943 to mid-September 1943," presiding Judge Ralph Alt said.
"As guard he took part in the murder of at least 28,000 people," he said.
An estimated 250,000 people died in the gas chambers at Sobibor.
Demjanjuk has already spent eight years in detention in Israel.
In the 1980s, an Israeli court identified him as "Ivan the Terrible", a notoriously sadistic guard at the Treblinka death camp, and sentenced him to death.
His conviction was overturned after new evidence showed that another Ukrainian was probably responsible.