Here's the problem, gmg, all kinds of people of every race, creed, color and religion commit crimes all the time. Black people commit crimes at disproportional rates, because they are disproportionately poor. Poor white people commit crimes at the same rates as poor black people BUT in much higher absolute numbers than black people - because they consist of a much larger part of the population. But it's seldom that petty crimes committed by white people end in death for them. So, it's easy for you to sit back and promote (or at least be so caviler about) the ultimate killing of someone for committing a petty crime when there's little chance that it will happen to your father, brother or son. That guys selling cigarettes simply should have been given a ticket, nothing more. He was there to harm people no more than your rep watch buying harms people (that's an argument for another day - but you get my point, we're talking physical harm here). And that big scary black man routine (he was 7'2 and 800 lbs) is overused. He was a person like you and I am. He should not have been arrested in the first place, no more than you should be arrested for crossing the street when the traffic light is red. He should have been given a ticket and allowed to live to become a better person in the future.
You ask who's at fault? The guy using the illegal chock hold, that;s who. That's why it's illegal. People prone to breathing problems die very easily when put in that hold. And under the law, it's a general principle that you take your victim as they come. Meaning, if you point a gun at a guy in an attempted armed robbery, you still get a felony murder charge even though you didn't pull the trigger when that guy dies of a heart attack. If you ram your car into the back of another car and kill the driver who had a eggshell for a skull when a normal person would have easily lived from the impact, guess what? You're still liable. And if you use an illegal chock hold and kill a guy with asthma, same thing.. you're responsible. That's the law my friend.
Back to crime for a minute. Specifically, White people use marijuana at much higher rates than black people, but black people are much much more lille to be arrested for it's possession. I came back to that point because the issue is not who committed a crime, it's how the government responds to it. And lastly, believe me, if cops were killing your unarmed kids in the back, you would be taking the other side of this argument. So, try and see this from someone else's point-of view, just for one min.