Okay so they have spotting scopes and tripods for sure. Now they could have just brought those for the sake of gathering accurate info on protests I assume are 100-300 meters away to pick out details better (ie Is that person pointing a gun or a dslr camera with a long lens?)
A modern AR-15 (most patrol car rifles) with a proper zero, consistent ammuntion and in the hands of a capable person (it's not hard it just takes regular practice) could easily be used effectively to engage man size targets with a guy on the spotting scope doing the target id I mentioned earlier to get the right guy.
With a basic bolt action precision rifle, even if it's chambered in the same round, could be used even more effectively with target id capabilities of the spotting scope using the magnification of better rifle optics. I bet they have one on that second tripod.
And honestly I'd prefer that over 50ish dudes with rifles with their own set of mob mentality like they had at Kent back in the day.