“Leave Robert Wagner Alone!”
Perhaps if he were leading a quiet life, but he is still is in movies and TV. For the Wood family, I can understand.
They still go after Nazi concentration camp guards and clerks in their 90’s despite their being obscure then and now.
If people commit a horrible crime, they should spend the rest of their lives always looking over their shoulders. Just because they are old and have hidden their crime well so far should not buy them any relief from the punishment.
That's a general principle. I have no idea if this applies to Robert Wagner or not but if the DA thinks that there is new evidence, it should be presented to a grand jury.