Even if he were to get death row (which I doubt), there are hundreds of death row inmates in Calif. and in the last 2 or 3 decades they've actually executed about 3 or 4.
Odds are that Peterson won't die until he's an old man.
Hard labor above the Arctic Circle breaking rocks is what they should do in the meantime.
And from natural causes.
(He'll probably outlive his entire family.)