I'll look at the net approval rating at https://www.natesilver.net/p/trump-approval-ratings-nate-silver-bulletin one week after at least one protestor got shot by law enforcement. It doesn't matter what agency the agent was from who shot the protestor(s). National guard or military counts as well, as long as it happened while they were on duty, responding to a protest.
If no protestors get shot during the second term I'll resolve the market N/A. If net approval is exactly identical in Silver's report, this resolves NO, since it didn't go up.
It's irrelevant for the market condition if the protestor survives. As long as they were hit by a proper, potentially deadly bullet, not rubber bullets or teargas or similar, it counts.
Edit: this has to be at a protest in the US.