doh ~
Actually, that's the very point under discussion here: did Ersland reasonably believe Parker was a threat at the moment he fired those fatal shots? It doesn't really matter whether or not Parker was, in fact, a threat -- only whether Ersland reasonably believed Parker was a threat at that moment. That's what the jury will be asked to consider. To do that, they'll look at the totality of circumstances.
In Ersland's favor:
1) Parker was part of a gang or group of people threatening violence, and Ersland did in fact see a firearm in the hands of one of those people. Courts have ruled that in cases where a victim is attacked by a group, each member of the group shares in creating the fear that the intended victim experiences, and thus each member of the group shares in the danger created by the intended victim's reasonable response to that danger. In the heat of the moment, it would be perfectly reasonable for Ersland to believe that Parker was armed, even if he did not specifically see a firearm in Parker's hand.
2) The backpack. If, in his last moments of life, Parker was reaching into his backpack, Ersland's belief that Parker was armed and a threat might be quite reasonable.
3) Where were his hands? If Parker's hands were underneath his body, and he was rolling around or moving such that his hands were not visible to Ersland during the moments before he fired, Ersland might reasonably believe Parker was armed and a threat.
Against Ersland:
1) The DA was very specific that there was "forensic evidence" showing that Parker was down and not moving at the moment those fatal shots were fired. If (for example) there was a straight line of blood from the head wound to a puddle on the ground beneath Parker's head, with no sign that Parker's head had ever moved once he hit the ground, Ersland's story of Parker shouting, moving, and rolling around would be inconsistent with the physical evidence.
2) Ersland's own body language on the video, which may not be consistent with body language one would expect if he was truly in fear for his life at the moment those final shots were fired.
3) Ersland's state of mind as evidenced by things he might have written or said to others before the lethal encounter took place. There's been at least one newspaper story (probably dozens by now) that went into this, and some of what was reported will probably be admissible in court as evidence of Ersland's mindset and prior intent. If the newspaper report is even 1/4 accurate, those things won't work in his favor.
Kathy
