When innocents get shot in places like Chicago, it's usually covered. I've seen several stories about children shot through the walls during drive bys or gang members killing children or family members of other gang members. When it's someone innocent, there is always coverage regardless of social/economic status.
But why should people care when it's just gang members killing each other? People are desensitized to it now due to the frequency with which it happens and the culture around it glorifying it. The reason you will always see school shootings covered more than gang members killing each other is because in school shootings, the victims are people whose lives still have potential. In gang shootings, it's simply the equivalent of the trash being thrown out. The dead in those scenarios have typically already proved that their potential and their benefit to society disappeared long ago.