The data below show the changes over time in both deaths from shootings at K-12 through college and also deaths from mass public shootings.
This data updates an earlier report that we had put out on deaths from school shootings in June 2014. Shooting deaths at K-12 schools make up over 78% of deaths at all schools, but despite an unusually large number of deaths so far this school year, both the number of deaths and the number of shooting incidents at K-12 schools has been declining over time. The graphs below prorate the deaths so far this year to assume that they will continue at the same rate, which is highly unlikely. After an unusually large number of deaths, these attacks tend to go back down to the normal rate for the rest of the year. As such the “true” regression lines probably lie in between the current actual data and the prorated rates.
The additional data from what we had previously reported is seen below (click on to enlarge). The updated excel file with the data is available here.
The longer the period of time that you examine, the greater the increase in deaths from mass public school shootings. Over shorter periods, such as the last 20 years, the rate is fairly flat. These data look at cases where 4 or more people were killed in an attack, and we follow the traditional FBI definition of the attack being in a public place and not part of some other crime such as a gang fight over drug turf, though that last part of the definition isn’t really relevant here. The two cases that occurred before 1995 were the Stockton, California attack in 1989 (5 killed, 32 injured) and the Olivehurst, California attack in 1992 (4 killed, 10 injured).
With regard to Mass Public Shootings at Schools, there was only mass public shooting at a school prior to the federal gun-free school zone act (data available here). Click on the screenshot below to enlarge.
Here are a couple op-eds here and here that discuss the debate over Michael Bloomberg’s claims through his various gun control groups about the rate of school shootings. See also here for a related discussion.