Mass shootings have nothing to do with gangs.

Your statement is patently false; gangs do commit mass shootings. While there is no 'standard' definition of one, let's use the somewhat accepted definition of 4+ humans shot. Gangs definitely do commit shootings that fall into this category.

That said, it's absolutely disingenuous for 2nd Amendment advocates to point fingers at marginalized groups (trans, the mentally ill, POC, etc) as the reason for mass shootings. This is a standard Conservative trope; point fingers at 'the others' in order to ignore the root cause of the issue which would most certainly reduce the severity and frequency of these happening in the US.

I'd like to point out though it would be highly unusual for someone to characterize violent gangs as "marginalized groups" even if it might truly be the case. I don't know if that's what you meant but I was having trouble following the train of thought from the gang comment by Kirk.

Gangs are often made up of POC. But; no, I wasn’t specifically including them in my statement about marginalized groups, yet I see how my statement could be seen that way.