Auschwitz bookkeeper goes on trial in Germany

Auschwitz German Nazi extermination and concentration camp survivors Eva Pusztai-Fahidi (L) and Hedy Bohm wait for the start of the trial against Oskar Groening in a courtroom in Lueneburg April 21, 2015.[Photo/Agencies]

"At some point you are there and the only thing left is the feeling: I am part of this necessary thing. A horrible thing - but necessary," he told the magazine.

Hedy Bohm, an Auschwitz survivor from New York who is attending the trial, said she wanted to see Groening declared guilty but saw no need for him to go to jail at the age of 93.

"Those who commit crimes today must know they will be held responsible in the future," she said. "And never again will they be able to just plead 'I'm a cog in the machinery, I didn't kill'.".