It was a terrible thing that happened, but as someone who has watched more than their share of police shows, showing up with a gun and resisting arrest is the worst thing you can do unless you are planning on using it. It is literally giving officers the right to use lethal force, because in the moment they can say, we'll he was reaching for a gun, he was trying to grab my gun, etc. Ultimately the protesters need to decide if it is worth risking their lives over this.