While I feel bad about his outlook on life at the end, I don't understand why some of you are defending him. He stabbed someone... you don't do that for fun. You do that with the intend to harm. As djheater pointed out, it's not as if he was in jail for tens of years. He was in there for (arguably) a ballpark fair amount of time for his action.
I remember reading something in the paper a couple months back about a proposal to make a holding facility for CA's aging prisoners. I think this would be a good thing. And in cases such as this, where the inmate has no family and no way to make a living at such a great age, it would be a needed social service for people to be allowed to stay in the prison doing whatever work they were able to do. Be it gardening, cleaning the facility, speaking to children about their experiences, and yes.. to those that could, some physical work.
I just don't mean 90-year olds. The main argument was that older prisoners (those getting into their 60's.. where you still have a lot of capacity and energy; just not enough to defend yourself against angry people in their 20-30s) were being abused by others and also had very different needs than most of the prisoners.