Its just murder. Obviously second degree or manslaughter depending on where she shot him. In the head would be murder. Somewhere else may be manslaughter. First degree would be hard. That’s planning the murder. Certainly the video does not show it. But all those people who respond to the quality of the victim rather than his right to live or at least her lack of rights to end his life, are ethically challenged.
It doesn't matter if he was, in anybody's estimation, a great all-around guy or a no-count white trash. Irrelevant. She killed an unarmed man by shooting him in the back. Was he trying to escape? Well, he was not a murderer (2nd degree burglary and possession of weed? C'mon) and attempted escape is not a capital offense.