1) I can’t show that it was absent before FPS became good enought because it wasn’t:
http://www.pewresearch.org/fact-tank/2014/06/17/why-timely-reliable-data-on-mass-killings-is-hard-to-find/
So Grossman is probably wrong on this:
http://www.killology.com/school_notes_preventing_violence.htm
1) I can’t show that it was absent before FPS became good enought because it wasn’t:
http://www.pewresearch.org/fact-tank/2014/06/17/why-timely-reliable-data-on-mass-killings-is-hard-to-find/
So Grossman is probably wrong on this:
http://www.killology.com/school_notes_preventing_violence.htm