Earlier quoted context omitted.
I don't understand what point you're making, but I have noticed that "google Chicago shootings" has become something of a racist dog whistle, so if that's not your intent there may be better phrasing with which to make it.
The point is black lives seem to matter only if taken by a white police officer. The BLM movement is quite silent regarding other black deaths.
There's an expectation that the police will investigate regular crimes and bring the criminals to justice. For crimes committed by police, there's no such guarantee. Why is it wrong for a movement to focus on watching the watchmen?
In any case, what are protests and rallies going to do against gang violence? You need social programs to keep kids out of gangs, provide poor families additional assistance, improve living standards and so on.