At least in the US there are observable trends of police brutality and mass incarcerations; in the UK, liberals and leftists are having to gaslight the country into believing there is racialized police violence problem in order to rationalize their support for the BLM agenda (only 13 black people have died in state custody in the UK over the last 10 years). And this comes after the left spent the better part of five years insisting that more police funding and a drastic increase in officer numbers would reduce rates of violent (particularly knife related) crime. It goes without saying that their present support for the "defund" narrative - itself little more than a simplistic anti-cop slogan - is insidiously hypocritical.
Though frankly I'm less concerned about BLM's objectives than I am about the Stalinism which encompasses it. Almost anyone scrutinizing, investigating, criticizing or contradicting the movement risks immediate ejection from polite society. Watching frightened liberals uncritically prostrate themselves at the feet of this corporate backed, American grievance campaign is beyond tragic. So in the same week as a man is convicted of a hate crime for calling someone a "leprechaun" in Scotland, it is now no exaggeration to claim that free speech, free inquiry and scepticism have bent the knee to this institutionalized quasi-religious victim culture.