That video of Dorian Johnson sounds very credible to me.
I live in an affluent, low-crime town, but you can regularly hear just a basic traffic cop taunting and barking at a simple pedestrian or driver if the cop perceives movement that he didn’t expressly authorize. I can only imagine such a situation in a less crowded area, if his target didn’t immediately respond, apologize and do just what requested, especially if black teens were involved in an area where there is a lot of black crime.
On some level this really isn’t that different than all the cops shooting dogs needlessly because of a perceived threat.
So jumping out of your cruiser and gunning down somebody is no different than shooting a dog.
For your own safety please stay in your affluent, low-crime town.