If BLM is a movement that campaigns against violence and systemic racism towards black people, then the questions are 1) what group perpetuates the most violence towards black people, and 2) does the dead black victim really care if the one who killed them was racist or not? They're just as dead, right?
Because, if "It's not a thing", then it doesn't sound like the person who said this is very concerned. And if they're not concerned, why should I be?
Also, why should I then add a new concern to the one I'm being told is "not a thing"? Especially when my concern causes much more death than the other concern. Just because a black person tells me I should care more about what concerns him over a more pressing concern, then I should care? I shouldn't care what I care about, I should only care what they say I should care about, and then only in the way they tell me I should care? Nope, doesn't work that way.
.