I just received a call back from the captain. He assures me that they were checking for fireworks, booze, and knives over 3 inches (city ordinance). He also plainly stated there was no ban on open carry or concealed carry of a firearm.
We spoke briefly about the tragedy. He tells me that there were a number of officers in the area of the victim at the time and it doesn't appear like there was any violence in that area -- that's all he'd say about that.