Sorry if I seem callous, we all come from different walks of life. I've been dealing with violent people in some form or another for most of my adult life, and I have no sympathy for people like Brown. He's not the victim, he's the victimizer. He chose to live by the sword, so to speak, and that choice has unpredictable consequences. I feel sorry for his mom. I feel sorry for people in wheel chairs who get gassed. (generally speaking, I don't know the whole situation). But heck I used to get with my friends and we'd pepper spray each other just for fun to make our wrestling matches more interesting. I get gassed with various crowd control agents at least once or twice per year as a training aid. That's not to say it's okay when it's used unjustly, but I'm never going to be able to place that kind of thing at a higher level of importance than maintaining order in the face of rioting with unpredictable consequences. I think it's very unfortunate that they screwed up what could have been a peaceful protest, but cities have been leveled by rioting that got out of control.
Again, mistakes are being made all around, but this is not a case of all good or all evil. The police aren't there just to indiscriminately harass everyone, nor are they movie caliber superheroes. They have a job to do, and they have to do that job with the same social, psychological, and physical limitations that everyone else is subject to.