So 10-12 out of hundreds/thousands of individuals? Then how come these peaceful protesters didn't isolate/restrain/identify/pepper-spray/anything these violent

So 10-12 out of hundreds/thousands of individuals? Then how come these peaceful protesters didn't isolate/restrain/identify/pepper-spray/anything these violent agitator individuals? I'd say that sounds like more than 10-12, or those 10-12 had a whole lot more "peaceful" supporters supporting/cheering them in their criminal activities.