Are blacks more prone to riots? Actually, I think arabic people are more so than blacks. Just look at the middle east. But if we are narrowing the range to only America? I would say they are more so than white people. They have rioted more than whites have during my my lifetime (since 81). And if Zimmerman is found not guilty, and the blacks riot, it will just be reinforcing this mindset that blacks are more prone to rioting.
Oh, and for all the idiots out there, Zimmerman is NOT white. He's as white as Obama is black (as in, not completely). He's more hispanic than anything. Yet they will attack "whitey" because Zimmerman appears white. Not all hispanics are brown.