It’s called “felony murder”: if you commit a felony, and someone dies in the process or in the escape, YOU are responsible.
That includes an observer dying of a heart attack during perp’s exit from a bank robbery.
In this case, Johnson was party to a felony (no question, it’s on video), and as he & his cohort were leaving his cohort died.
Moreover, his cohort assaulted a cop, and his cohort died - be it while escaping or re-engaging the assault (covering BOTH standard theories of the event, be it Brown being shot in the back while fleeing or submitting, or in the front as he returned to beat the cop again). He admitted to being a party to the incident, so he’s screwed no matter what’s proven.
“In this case, Johnson was party to a felony (no question, it’s on video), and as he & his cohort were leaving his cohort died.”
His theft was not a felony. The assault on the clerk is borderline.