There is some validity to the skewed narrative of protest coverage.
I've done livestreams from among them many times, local news tends to stand where the police tell them and repeat what the media liaison officer tells them. Their coverage tends to start after the party gets going.
The easiest way to see through it is to find photos of just before and just after the unlawful assembly/orders to disperse. That takes out about 80-90% of participants right there. Everyone left at that point is pretty hardcore. Some are down to rumble (and honestly always were) or may have begun rumbling which caused the unlawful assembly order. Some more get caught up in the emotional wave with them, but a good half or so are just the types with more heart than brains and are still trying to make some kind of valid point, despite the futility of it.
But the vast majority left when it turned bad and wanted no part of it.
Ferguson was a classic case of this. Vice had a stream on the ground walking along with a group of people from the neighborhood around West Florrisant, night sky lit with multiple fires. They went to the protest, left when ordered, went home, and then looting and fires (across town from the city hall protest). They were devastated. They were watching total strangers destroy their city.
This incident today is harder to track in that context since violence has been escalating since the previous night. This was an issue that made the rounds when the decision was made and lots of outside groups got in on it. Plenty of time for lots of thrill-seeker vacation protester types to jump in, as well.
But the same principle exists, this is hardly a broad cross-section of America being seen in this.