You've also got to take into account the majority of gun violence in general. It's really not hard to extrapolate the political leanings from a demographic when that demographic's political leanings are known.
I'm not going to outright state it because it could be seen as "hateful" by those who want to reject facts in favor of feelings and a false narrative, but you can look at the violent crime stats by the FBI as a report and kinda see where I'm going at with this.
The left wants gun control, I say we give it to them. If you are a registered Democrat, you simply cannot own a gun, pure and simple.