Why can't it be both? Especially when guns are so interwoven into the culture.
So it's not a mass shooting if the person is black and the crime is personal? What led you to come with that criteria? I tend to think "A mass shooting is a violent crime in which an attacker kills or injures multiple individuals simultaneously using a firearm." is a pretty fair definition. You know "mass" as in several individuals involved and "shooting" as in a firearm was involved. Keep it up with the mental gymnastics though.
I'm not sure you can even have one without the other tbh