The majority accepted is 4 or more injured or killed, not including the shooter (gun violence archive).
The DOJ version is 4 or more killed, which is just the mass murder definition with a shooter, leaving out a lot of incidents.
In either case though, the motive is irrelevant because its not going to be known at the time.
madcaesar@lemmy.world 1 week ago
I still think your distinction is important. They are both tragedies of course, but it’s important to know and understand the cause.