1. There is a certain extent that you go to for these types of events. In the article, it stated that one man yelled at an officer, "You don't get to murder us and get away with it!". I agree strongly with that. There shouldn't even have to be riots and protests like this. It does not matter what race the officer was. No shots should have ever been fired. Police officers panic and they abuse their power, I do agree with that. When they called in the National Guard I'm sure it was only to scare the protestors. I feel as if that is all they were called in for. 
2. When Martin Luther King Jr. protested he said: "that all men are created equal." That was such a big movement that will forever be remembered in history. Now, there is not one leader of the protests. These protests sometimes get out of hand but they are for a good reason. Maybe, they aren't as well organized, but they are for a very good reason. This website states that yes, Martin Luther King Jr.'s protests were very peaceful and organized: http://www.csmonitor.com/USA/2012/0115/Martin-Luther-King-Jr.-8-peaceful-protests-that-bolstered-civil-rights/Montgomery-bus-boycott-1955-56
3. Yes, there are definitely two different groups. They are racially charged, they feel as if they have to protect their race and they are completely right for that, both of the groups.