Mass Shooting Fatalities in America

Source: The Stanford Mass Shootings of America (MSA) data project

The Stanford Mass Shootings of America (MSA) data project began in 2012 in an attempt to assemble a list of mass shooting events in America. It is important to know that the information is collected from online media, and is not a comprehensive, longitudinal research project. Far more incidents are included for later years, but this may have far more to do with availability of reports as frequency of such incidents. According to the MSA website, "a spike in incidents for recent years is likely due to increased online reporting and not necessarily indicative of the rate of mass shootings alone."

The MSA defines a mass shooting as "3 or more shooting victims (not necessarily fatalities), not including the shooter...not be identifiably gang or drug related", where "the motive typically appears to be indiscriminate killing." Due to differences in definition, this database may include or exclude events that are listed in other databases of mass shootings, such as the MotherJones.