They would've gotten him for anything they possibly could. Murder, attempt of murder, wreck-less driving, speeding, driving without a seat belt, damages to the deli he shot up. Anything he did that was illegal, they would've charged him with it. No matter how small it was.
I don't think he would've gotten the death penalty though because it's been barred in California. I guess he could've but California hasn't executed anyone in years, it's barred as of right now and they have no plan of executing any of the 750 people on death row anytime in the near future.
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“And may you grow to be proud
Dignified and true
And do unto others
As you'd have done to you”