I think the context of the riots is drastically different and that plays a huge part on perception.
The "White" riots as they're labeled, while still criminal activity that should be shunned by people, are riots of joy at an accomplishment of their city.
The "Black" riots are from a point of anger and aggression(whether you believe they are warranted in their reaction is a personal opinion)
No matter your skin tone, rioting, destruction, vandalism and assault are criminal offenses and participating makes you a criminal. It's understanding this that makes the difference in how people perceive you.
On a side note, why are all these riots and showings being made for criminals, when people like Eric Garner are laid to rest quietly? Gray and Brown were fleeing police custody when they were killed, Garner had stopped walking and given his hands in restraint, yet we have a few peaceful protests over it and it goes away; while we have a known drug dealer and a criminal's deaths tearing our city apart. I understand solidarity but when you defend scum, you start to look like scum too. Stand up and be heard for the ones worth it, not the detriments to society.