It seems like hardly a day goes by without another report of a mass shooting somewhere in America.

Yes, and the evidence is abundant, as you'll see right here. But who's doing the shooting? What are the media neglecting to report? Thanks to the efforts of a dedicated group of researchers, you now have your answer.

What is a mass shooting?

This site defines a "mass shooting" as an incident in which four or more casualties (reported injuries or deaths) occur.