A 94-year-old former Auschwitz concentration camp guard faces a prison sentence of up to 15 years if found guilty by a German court on Friday as an accessory to the murder of more than 170,000, most of them Jews.
Prosecutors in the city of Detmold say Reinhold Hanning, who volunteered to join Adolf Hitler's SS at the age of 18, participated in the systematic killing of 170,000 people between 1943 and 1944 at Auschwitz.
The defence argues that Hanning's mere presence at the camp is not proof that he was directly responsible for the murders and is calling for acquittal. Prosecutors are working on the legal reasoning that he can be convicted for helping the camp operate.
Hanning was present at the camp during the so-called Hungary Operation, which saw the deportation of 425,000 Hungarian Jews to Auschwitz during a period of three months in 1944. The majority of them were gassed on arrival.
Fifty-seven Auschwitz survivors and their family members joined the proceedings as co-plaintiffs, as is permitted under German law.
The court heard witness accounts of atrocities committed at the camp, including the hanging of a 16-year-old boy who had stolen a piece of bread and the beating death of a man who lost his glasses in the shower.
Hanning seemed alert during the case, but avoided eye contact with the witnesses. During an April statement to the court, he apologized to the victims and said he felt ashamed for being a member of a criminal organization and doing nothing to stop it.
For decades after the war, German courts argued that the top Nazi leadership was principally to blame for the mass murder of Jews and that lower-ranking individuals in the Holocaust machinery were bound by a chain of command and, therefore, less culpable.
That approach changed radically after a legal precedent set by the 2011 conviction of John Demjanjuk, who was found guilty by a Munich court as an accessory to the murder of more than 28,000 Jews while he was a guard at the Sobibor camp in occupied Poland.