Being British I will try to keep my own opinions out of this comment, which I am posting only because I see grom comment threads on UK sites that many Americans sincerely believe we in the UK and presumably the rest of Europe should be as angry as "Americans" about this incident. Americans is in quotes there because the people who post such comment seem to think they speak for all Americans but that is simply not the case.
Having said that, I do agree the killing of George Floyd was an unnecessary over-reaction which we are aware from mainstream news and internet sites, all too often typifies the reactions of American police, to people of various minorities who dare to question why they are often treated in such a heavy handed way for what are at worst trivial misdemeanours.
What deters many of us from offering wholehearted support to the protestors is that the campaign to demand justice for the victims so often descents into looting and destruction of property. This not only insults the memory of the victims, but totally undermines the claim that the protests are about ending injudtice and oppression.
Thus, speaking only for myself, the best course is stay out of the debate. While some troublemakers on the extreme left are always eager to give the impression we have inter - racial problems on the same scale as those of American inner city communities this is simply not the case. There is racism, there is even black on black racism - the gang wars in London between Pakistani and African gangs, though not widely reported, are brutal, but the majority of us manage to get along in a spirit of tolerance and mutual respect. Taking sides in America's racial problems would not help at all.