You're right. Today's culture (with the left) is to excuse the violence because they assume the cop was racist. We don't know all the details yet.
Violence is never acceptable, no matter what the "reasons" are for it.
Other people are killed every day because of people who have no conscience and the left tends to excuse it. IF this cop shot the kid for no justifiable reason, that is bad. What the rioters did was intentional, planned and inexcusable and they need to admit to that.
Shootings by police are always investigated and action is taken depending on the findings. Keeping a spotlight on them ensures that they will act in a fair manner. The rioters don't care about details. They heard a few things and that was all it took for them to take to the streets and terrorize the neighborhood.
For angry mobs to burn down cities, shoot at people and carry on with violence says more about them than the Ferguson police dept. At worst, the dept. has a bad cop and we know nothing about the guy yet. We know plenty about the rioters at this point and they have no excuse for the violence they have demonstrated. They used the shooting as an excuse for looting and destroying the neighborhood. They don't have the maturity or intelligence to discuss it in a reasonable fashion or wait for more facts. They were too quick to start with the violence and that makes them worse than the cop, even if he is guilty as hell.
I find it much more frightening that people (like ones in Chicago) kill people routinely and think nothing of it. How can some so readily accept that as the world we live in, yet jump to conclusions and act as judge, jury and executioner when some irresponsible talking heads start crying racism. You'd think that was the worst crime one could commit. And violence is treated as a normal response to the mere allegation of racism. It's no different than excusing Muslim terrorists of murder because they were insulted.
Being offended is normal and not a crime punishable by death. It takes a mature person to rise above it.
The violence has gone on for days, though seems to be ebbing. It will end when there are no more places to loot, not when the truth has come out. That indicates the real reason behind much of this. Are people talking about the shooting as they sit at home going through their new merchandise stolen from the local shops? I doubt it.
The militarization of police has escalated under Obama. The same people who send SWAT teams armed to the teeth even when it's one person they seek doesn't agree that the average person would ever need to protect themselves against criminals.
Some store owners fought for their property. They were armed. They still have their stores and the means to support their families. That is a good thing. When these riots break out, the innocent people are quickly outnumbered.