guns are definitely a problem but not the root issue here. This brother was so upset about being compared to other people in his city that he doesn't like that he was ready to take someone off the earth but had the presence of mind to ensure that enough people joined his livestream before he started airing his grievances.
He didn't set out to kill white folk or cops, the target of his anguish was Black men or n*ggas as he put it. 4 people in total have been charged with the murder in the OP so it doesn't necessarily mean that he's the triggerman but I believe it's worth investigating why these brothers want to end the lives of Black people when they get upset.