Despite the humane and civilised bias in the Norwegian penal code, I think it is fairly widely acknowledged that if this man were to be released after the maximum time served, 21 years or so, he would not survive a week in Norway.
The man is a walking cadaver doomed to a living hell in isolation for the rest of his natural life. Death will be his only release and in truth it would have been a kindness to have put a bullet through his brain on conviction.
Try to imagine what it would be like to live in that cell for 40 years without any human contact. Personally, I think it was fairly evident the man was insane and should have been detained without limit in a secure mental institution free to associate with all the other homicidal lunatics for the rest of his life.