Are mass shootings really random events? A look at the US numbers.

http://www.empiricalzeal.com/2012/12/24/are-mass-shootings-really-random-events-a-look-at-the-us-numbers/?utm_source=rss&utm_medium=rss&utm_campaign=are-mass-shootings-really-random-events-a-look-at-the-us-numbers