> the latter has far too often been done right before a killing spree There's an important point that should be made here. http://en.wikipedia.org/wiki/Confir

> the latter has far too often been done right before a killing spree There's an important point that should be made here. http://en.wikipedia.org/wiki/Confirmation_bias#Biased_search_for_information http://en.wikipedia.org/wiki/Confirmation_bias#Biased_search... You may have good metrics on the number of incidents that were pre-dated with announcements, but you probably have very bad metrics on the number of announcements that were followed by incidents. There's no way you can make a statement about how strong the link is without that information.