This is a two part answer; a message over how punishment is necessary, and also about this mans case.
Age shouldn't garner leniency or grant freedom. In the same way a smoker will not escape the consequences they bring on by their actions, people who perform such horrific acts such should be held accountable. It would be nice to be able to "forgive and forget", but (to quote Movie Bob) "we do not live in a perfect world", and whilst some would view the act as kindness, others would see it as a weakness. Compassion should not be taken into account for such heinous crimes against humanity, and judgement should be passed in a fair court of law.
Concerning the defendant, the card evidence is shady. I do not have an opinion on whether the ID card is fake or not, but believe that further investigation should be put into action to give the best possible answer. Also, though his family are obviously looking out for his wellbeing, I do not know whether trying to persuade the court that he is too frail to stand trial to get him off the hook, so to speak. This is obviously not evidence, but if they use this as a ploy to shield him, then
If the man has, as so many people believe, had nightmares or regretted his actions, then why not hand himself in? He has had plenty of time for this guilt to naw away at his conscience, even into old age, but even now he can't admit his part in all of this? If he is guilty of any crime, then by refusing to admit it he continues to spit in the faces of everyone murdered in the camps, in the streets and in foreign lands: how do you find forgiveness with such an act?