Contact one of the legal clinics in one of California's law schools to see if they can help.
In no way am I offering you legal advice, and in no way has my comment created an attorney-client relationship. You are not to rely upon my note above in any way, but insted need to sit down with counsel and share all relevant facts before receiving fully-informed legal advice. If you want to be completely sure of your rights, you must sit down with an experienced criminal defense attorney to be fully aware of your rights.
Mr. Deasey's suggestion is excellent.
I would add that some of the bigger, "blue chip" law firms such as Latham & Watkins or Gibson Dunn or O'Melveny & Meyers have appellate departments that, which not free, are outstanding. Good luck.
I have to add that if DNA was a major factor in his conviction or possible exoneration the Innocence Project is your best bet. Google them and good luck.
Because I was recently congratulated by an Avvo questioner for having the courage not to use a disclaimer, let me make it clear that I have always answered questions subject to the Avvo general disclaimer. The answers I give are for educational purposes and not to be relied upon for legal advice. No attorney-client relationship is intended or established by virtue of these answers.