A German court heard Friday from a 100-year-old man who was being tried for his role in the guarding of Nazi SS camps during World War II.

The defendant faces 3,518 counts of accessory murder at Sachsenhausen concentration camp in Berlin. He allegedly served as an enlisted member for the Nazi Party’s paramilitary wings between 1942 and 1945.

German news agency dpa reported the defendant, Josef S., stated on the second day in his trial before the Neuruppin court that he did not know about the Sachsenhausen camp.

Two witnesses from France, the Netherlands and France earlier testified before the court that their fathers were murdered at Sachsenhausen because they had been fighting against the Nazis.

The defendant was found fit enough to stand trial, despite his advanced age by authorities. However, the hours that the court will be in session will be restricted.

Between 1936 and 1945, Sachsenhausen housed more than 200,000 people. Tens of thousands of prisoners died from starvation, illness, exhaustion, forced labor, and other causes.

Although the exact number of people killed varies, there are upper estimates of around 100,000. Scholars suggest that figures between 40,000 and 50,000 are more likely.

Cyrill Klement, prosecutor, stated that the defendant “knowingly and willingly assisted and abetted it at least by conscientiously carrying out guard duty, which was seamlessly integrated in the killing system.”

Additional hearings will be held through January.