I watched the video several times.
The cop exited the car & fired in less than 2 seconds. He took no time for a warning. He took no time to assess the situation. I doubt he had time to speak. Basically, he jumped out of the car & started firing.
It looks like murder to me.
I wonder if he saw the surveillance video I found after I posted this thread. Go back a few replies and watch the youtube clip I provided. Perhaps the police saw it before the cops arrived since it was at a public park? Note the person at the picnic table that later leaves after the boy points his toy gun at a person walking the path. I believe this video was just released.