Does the presence of the media aggravate the protests, who want to be seen? This sounds like relativity: the presence of an observer changes what is observed. Call it the "staring" or "kibitzing" effect.
Wikipedia attribution link for St. Louis Gateway arch picture. My last visit was in November 1998.
Update: Later Tuesday
Police shot and killed a man in St, Louis wielding a knife. There are reports that the man dared police to shoot him, after a theft in a convenience store,