By the way, has anybody actually looked at the site I mentioned at the beginning of this thread of discussion?
I have. Interesting numbers.
Different people use different sets of information, maybe different time periods . Maybe they use different definitions of the events they catalog. That accounts for the difference in numbers used in various places. It ain’t rocket surgery to figure this out.
Some sources, like the Gun Violence Archive (oft quoted by the media) use a lenient definition that includes shootings that most people would not consider a "mass shooting". The GVA definition of a mass shooting is "an incident in which four or more people are injured or killed, other than the shooter." Their figures include shootings that happen in homes. So, when one family member shoots four family members, it is a mass shooting.
The criteria used by the Violence Project are the same as those used by the Congressional Research Service:
"a multiple homicide incident in which four or more victims are murdered with firearms - not including the offender(s) - within one event, and at least some of the murders occurred in a public location or locations in close geographical proximity (e.g., a workplace, school, restaurant, or other public settings), and the murders are not attributable to any other underlying criminal activity or commonplace circumstance (armed robbery, criminal competition, insurance fraud, argument, or romantic triangle)."
The key differences are:
- four or more injured or killed vs. four or more victims murdered with firearms
- inclusion of private shootings vs exclusion of private shootings
- inclusion of shootings attributable to underlying crimes vs exclusion of shootings attributable to underlying crimes
All of these differences make GVA's numbers much higher than VP's. Most other sources seem to use criteria similar to VP's, given that their numbers are much closer to VP's. GVP's numbers are outliers, which makes me question why the media nearly always uses GVP's numbers.