Did you click through the link that post had? It goes to https://medium.com/@Jeff_Jackson/review-of-incident-in-charl... which is pretty long, but about half way though shows an attack on protesters by police. Search for this:
Here is what it looked, sounded, and felt like from the perspective of the protesters as the second police unit quickly appeared in front of them and detonated tear gas and a flashbang
From then on it goes into a lot of depth about the tactics the police used to trap the crowd, teargas them and shot them with pepperballs.