“There is one not-so-tiny flaw in all of these theories for the increase in mass shootings,” James Alan Fox, a criminologist at Northeastern University in Boston, wrote for Boston.com in August. “And that is that mass shootings have not increased in number or in overall body count, at least not over the past several decades.”
Fox cited a particularly broad set of FBI and police data that counted shootings between 1980 and 2010 in which four or more people were killed: The average pace was about 20 mass murders per year, with a death toll of about 100. Casualty counts fluctuated wildly — some years would have almost 125 dead, but then be followed by a year with fewer than 50 mass shooting fatalities. Far steadier was the number of attacks, which usually stayed at fewer than 25 per year.