Most of what is known about spontaneous, disorganized and occasionally violent collective gatherings emerges from a very limited number of studies on specific time periods with a limited number of cities. Perhaps the most prominent of these efforts was put together by Seymour Spilerman who explicitly attempted to investigate the validity of many of the claims put forward by the Kerner Commission.
In an effort to improve upon this, The Lemberg Center for the Study of Violence undertook what amounts to the largest evaluation of these activities with a total of approximately 4000. This effort was put together with a meticulous evaluation of news coverage. In these data, many variables were coded. We are only just now getting around to cleaning them and soon making them available. Several graphs and figures from these data are provided below.