The video does not look good for the cop, no matter what went on before the final act. Kid's stumping diagonally away from him with no move on the cop when the cop opens up, no apparent reason to jump to 'shoot to kill' and with the entire mag at that.
Still, pretty good chance the jury will fail to convict unless there are some major shenanigans in the pool and voir dire, which will only pour gas on the anger in the Black community if it happens. Wouldn't be surprised to see the Feds step in and prosecute.