The trial has begun for a 100-year-old man who is accused of being an accessory to murder during World War II.

Josef S. was a Nazi SS guard at the Sachsenhausen concentration camp in Germany during the war.

He was reportedly 21 when he began serving as a guard in 1942.

Josef S. is charged with more than 3,500 counts of accessory to murder.

According to the BBC, Josef S. does not plan to address the allegations during the hearing. However, he is expected to speak about his “personal circumstances” Friday.

A medical evaluation was done on the suspect, which confirmed that he was fit to stand trial, which is expected to go until January.