That's not so far, for a mechanical probe or for a traveler with, say, a 2000-year lifespan. That being said, I don't see any need to invoke aliens (yet).
There was originally a "Womens' March" scheduled months in advance. It was repurposed to a "March for Life" in the wake of the shooting. It would have been tempting, for someone sufficiently evil, to try to take advantage of such a large event by staging a shooting and repurposing the protest.
Date on that tunnel digging story?