They define mass shootings as “incidents when at least four people are killed or wounded, including the gunman.”

There is a shit ton of gunmen who are listed at 'Unknown' on their website. Typically, 'unknown' assailants are associated with gang activity. If gang shootings are now being classified as mass shootings, we don't have a mass shooting problem, we have a gang problem. Which is what is really going on with the United States. No one wants to talk about young male black-on-black violence. Which more gun laws are not going to help.