If you are concerned about police violence, I can understand that. I share your concern.
However, if you are concerned specifically about police violence toward one single ethnicity, then frankly... you are a racist. Around 400 White people are shot by the police every single year. More than one a day. For every Black person killed by the police, two White people are shot. Do White Lives Matter? Meanwhile, Hispanic fatalities are nearly equal to Black deaths. Do Hispanic lives matter? At all?
I realized the other day that I know, by name, a large number of African-Americans who have been shot by the police. When, where, the details of what happened. Black deaths get a lot of publicity and news coverage. However, I can't honestly name any White person shot by the police, even though more than twice as many are shot. I'm struggling to even think of one. Should I also care if a White person is killed? Nor can I think of any Hispanic individuals. Should I care? I think so, and if the BLM movement does not agree, then no - no, I can't support it.
There's a popular cartoon showing a man with a firehouse, spraying water at a house which does not appear to be on fire. Meanwhile, the other house is burning. BLM supporters pretend that only the Black house is burning, and its racist to even express concern about other houses. That's simply unreasonable. Police violence affects all races. It's not solely a "Black" problem. If you are genuinely opposed to racism, then you can't define police violence solely in terms of race.
I've also realized that not one of the African-Americans I know is out there protesting, wearing BLM t-shirts, or even talking about George Floyd. George Floyd's own brother told people to stop. The BLM movement is often said to represent Black people, but it doesn't. It's a very narrowly focused subset of the populace, which advocates for an extremist political ideology, and most BLM supporters are actually White 'activists'. Racist white activists are exploiting this issue for their own political agenda. Normal people don't want to defund the police. They understand that we need police, and that crime is a much bigger concern than the occasional instance of police brutality. The reality is that drunk drivers kill way more people than the police do. In addition, murderers murder way more people than the police do. The primary reason police are violent is because people are violent toward the police. That's a fact. When you attack the police, you are causing police violence. If you are doing that, then YOU are the problem.
The BLM website claims that Black lives are being "systematically" targeted for "demise". This is utter nonsense, an exaggerated false narrative. The United States may have a sordid history of race relations, but the United States also fought a very long difficult war to support the abolition of slavery. Yes, American police departments may have issues, but they are not deliberately implementing a genocide. There are lots of Black police officers, and Black politicians, and Black business owners, and Black generals. There are also Black drug addicts, sex offenders, murderers, and thugs.
Ultimately, while I sympathize with George Floyd's family, and I think the arresting officer should be held responsible for criminal negligence resulting in Floyd's death, the reality is that George Floyd used meth, and fentanyl, and he was convicted of armed robbery. He didn't deserve to die, but he wasn't an innocent angel. You are well within your rights to protest and demand that police reforms be implemented, but if you are setting cars on fire, robbing stores, throwing rocks, or hitting people in the head with a skateboard, then frankly I hope the police arrest you, and I won't be protesting if they treat you roughly.