Whatever crimes Marc Traylor may have committed, he wasn't the person who shot dead his accomplice, Laroy Brown.
Both men were shot during an alleged robbery by an off-duty police officer. Brown died of his injuries while Traylor was arrested after he sought medical help for his gunshot wound.
According to the Felony Murder Rule used by some US states, Traylor is liable for Brown's "murder". This perverse rule shares similar characteristics to the English Common Law Principle of Joint Enterprise, allowing for the over-prosecution of an accused who is blamed through a process of Collective Liability for the actions of another.
In the UK, such a prosecution might be unthinkable when the "victim" is a fellow suspect. But in California, along with several other states, it is considered perfectly legitimate to pass indirect liability for the death of one suspect to another.
This is not sophisticated justice in action: it is a disproportionate abuse of judicial power. When a democracy fails to treat ALL of its citizens fairly for their individual actions alone, including those who are accused of acting beyond the law, injustices will occur which undermine and debase the very society it seeks to protect.
You can read more about Traylor's Kafkaesque prosecution HERE