This is Pontius Pilate in full action.
Mayor gets what he wants ('clean' hands), 'top cop' gets what he wants (pass the buck), #BLM gets next to nothing but a pat on the head (because the perp isn't likely a #BLM dues-paying member), and the beat cops get shafted - unless they get their own lawyers and sue the everlasting shit out of all of the foregoing.
Annnnd again, the lawyers win...
YUP