The police are much more likely to avoid prosecution than anyone else filmed breaking the law.
Rioters are breaking the law and should be arrested. Protesters on the other hand are not breaking the law and are protected by the constitution.
http://www.cnn.com/2017/04/14/us/georgia-gwinnett-county-officers-fired-video-trnd/
Again, police should be arrested if they actually break the law. But only if they break the law.
And many of the highest profile accusations against police have not involved police that have broken the law, at all.
However, protesters are often breaking the law and should be arrested.
The violators are often for rioting.
But there can be other violations as well. (Illegally blocking a highway, trespassing, vandalism, etc)
Again.
Dems still aren't denouncing violent rioting and illegal protests as a form of expression
The law need to become FAR more punitive for illegal protests (which is finally happening) so that law enforcement can make examples out of these rioters.