In defense of the police, in this case, everything is proceeding the way you would expect it should. The trooper was fired, and now he's going to be up on serious charges, probably with some jail time. But, if that video didn't exist, I feel pretty confident that his statement after the incident, which wrongly said the victim had acted aggressively, would have been believed by his colleagues, and much of the public, especially the conservatives. With the existence of the video, there was no real question, and no real choice for the police force, but to act against one of their own.
Just a side point here: this also shows how racism can victimize white people too. Think about it: not only did this result in a black man being shot for no reason, it will also end the career of a white man, and possibly result in him being behind bars. Presumably, he really did panic, and assumed his life was in danger, or he wouldn't have shot. But how could he perceive anything here as a threat? If it had been a fellow white person who had reached back in the car for his license, especially a rich, well-dressed white person, I'm betting he wouldn't panic that way. So, in that sense, he may well be the victim of his own racial prejudices. He saw a threat where one did not exist, overreacted, and ruined his own life. This is one of the ways in which white people, too, have a real stake in trying to combat these negative racial stereotypes and irrational reactions. They hurt us all, no obviously they heard people of color far more directly and severely.