A 100-year-old man who worked as Nazi concentration-camp guard during World War Two refused to make a statement Thursday as he went on trial for allegedly assisting in the murder of more than 3,000 prisoners. The man, only identified as Josef S due to German privacy laws, obscured his face with a binder as he entered the Neuruppin state court in a wheelchair. The man is alleged to have worked at the Sachsenhausen camp—where an estimated 40,000 to 100,000 prisoners were killed—between 1942 and 1945. He’s charged with 3,518 counts of accessory to murder and is the oldest Nazi-era defendant to stand trial to date. Authorities have judged him to be fit enough to stand trial despite his age. Since the war, the man has reportedly lived in the Brandenburg area, where he worked as a locksmith.