Mass shootings are mass shootings. Also gangs are well know for shooting tons of innocent people. So your argument is hog wash.
It is just an outright lie which these leftists play. They claim to be studying and collecting data on "mass shootings" only the exclude data from the vast majority of mass shootings simply because they didn't like the results they got.
Bullshit. I worried every day about sending my kids to school where some nutjob fellow student could murder them. I never worried about them being victims of gang violence. That would have been really, really random. My son actually knew someone who was murdered by a mass shooter -- not a gang member -- at a school.