I have been to a few rallies/vigils/marches lately and all incidences of violence that I have witnessed either in person or through media has been instigated by the police. As far as I know,every documented case where a formerly peaceful crowd turns into chaos has been started with police shooting pepperspray, teargas, or whatever into the crowd.
I find it really hard to not come to the conclusion that the police is desperately trying to set a narrative to justify a history of violence by escalating more violence, but please, someone, restore my faith.
(I say 'individuals', not 'protestors', because the latter are peaceful people. The instigators are rioters and looters, a small minority of the people hiding within the former group.)
The other 25% has been initial violent action from the police. Things like shooting gas and charging forward when protestors were simply standing still.