I think the whole thing is a vicious cycle. I think we all know that there are racist LEOs, and that there are non-white criminals. Where I think the biggest problems lie are in other LEOs (not all) covering up, denying and/or ignoring those who are racists and use racial profiling to harass members of other races (I don't believe this is just a black/white issue), as well as those who should be charged with DV, DUI, theft, assault, and a number of other crimes. In addition to those who refuse to call out a co-worker for bad behavior, there are also DAs, judges, etc. who do their best to avoid prosecution in many of those cases.
On the other side of the coin are those who see one LEO act that way and assume they're all that way. The next time these people have encounters with LE, they're going to be less trusting, respectful, polite, co-operative or whatever words fit. The same is true for friends, family, neighbors, and others who witness the harassment of one person, and expect it to be them the next time. As more of them start treating LEOs with hostility, more LEOs are going to start expecting that behavior during any interaction with a member of that race, ethnic group, age group, religion, etc., which will just lead to more distrust (and, most likely, hatred.)
I really don't know what the answer is. It's very possible that this young man pulled out the gun because he had seen and/or heard about too many others being killed by LE to feel totally comfortable, these boys/men may not have even been the shoplifters (I haven't heard anything about the shop owner identifying them) and he was just tired of racial profiling (which the officer wasn't doing from what I've seen and heard.) I wouldn't expect the officer to first tell him to drop the gun with all of the upheaval there has been recently, and he had no way of knowing the safety was on so he could possibly have warned him first. There was also no way for him to know that the others he had been with didn't also have guns, and they were pretty much on all sides of him. He's lucky it wasn't a group looking to kill a LEO or two, or another person could have shot and killed him when he fell after he shot. MOO