If that is the case, and a perverse incentive exists for cops to arrest the innocent, then we should see this occurring all over the country and across all racial groups
Non sequitur - we'd see it only if it were commonly the case that someone who knew of it had motive to bring it to light.
I showed that your conclusion doesn't follow from your premise ... which is what "non sequitur" means.
Regarding the motive to bring it to bring the perverse incentive to light, it is possible that an institutional cover-up exists nationwide
Red herring. There need be no nationwide institutional cover-up, only a collection of local 'blue walls of silence' - against which our battered Christian Ethos is far-from-reliable protection (IMO you were more right than wrong when you said it "existed", past tense).
What? This is not Ad Hominem...honestly, are you taking psychotropic drugs? You have just shown the world that you do not understand what “non sequitur” and “red herring” mean. Just a reminder, you are the one that suggested that a perverse incentive exists for policemen arrest the innocent and plant false evidence. I employed reductio ad absurdum and you shout “non sequitur” and “red herring”. Go figure.