Does anyone attach any weight to decades long protestations of innocence?
I do, to an extent. Our system apparently requires an acceptance of guilt as part of parole, and therefore refusing to accept your guilt leads necessarily to additional time in prison. (This is a problem which needs reviewing, but I have no suggestions.) Before Michael Howard extended Bamber's tariff to whole-life, he was serving life sentences with a tariff of 25 years. This meant that he would have been eligible to apply for parole after 25 years (4 years ago). However, protesting his innocence throughout that period removed his parole chances.
I understand that now he has a whole-life tariff his campaign is just something he does without any cost to himself, but previously, it did have a cost (the loss of possible parole). Obviously that cost has to be weighed against the potential benefit of being found innocent and released early.....but nonetheless, there was a cost to Bamber in continuing to protest his innocence.
I don't follow these things closely. Are there many cases of people protesting their innocence and thus losing the right to parole who were actually guilty all along? There are many tragic cases of the innocent who protested for years and stayed in prison way longer than they otherwise would, but is there much history of the converse?