I watched the video from S. Carolina. Absolutely appalling. This former trooper should go to jail.
That said, what would have happened IF the encounter would not have been recorded? Here's my guess:
1. The State Trooper officials would back the officer and claim that it was a justified shooting, that the suspect made a threatening move (perhaps attacking the officer or, presumably, going for a gun) thus justifying the use of potentially deadly force.
2. Unquestioning lick spittles for the police, and authority in general, along with out and out racists would emerge from the woodwork to fill social media, blog-o-sphere and comment sections on web news sites with claims about how the trooper was a hero, was fully justified, that the suspect had it coming for this and this reason, etc.
3. The same people referenced in #2 would launch a crusade to dig dirt on the suspect and portray him as a gangster type lawbreaker who, if he didn't actually have it coming in this instance, certainly had it coming to him and this was karma and just desserts.
4. The trooper would get suspended for a period of time but allowed to return to his job.
5. No action would be taken to hold the trooper accountable.