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.
1. They are given rubber bullets and mace without any form of de-escalation training, so they just use the tools they have at their disposal.
2. Just like any kind of organism, the police force needs to preserve itself and make sure it is necessary. The military doesn't like peace, and the police cannot thrive with peaceful protests. They do what they see fit to make themselves irreplaceable.
From what I've seen, teargas and mace are used after a small minority of protesters become violent and the crowd is lawfully ordered to disperse.
I can't say if these are the right tactics, but I have not seen police use these things for no obvious reason.
The one situation where this wasn't the case is when peaceful protesters were blocking one of the two roads that was going to be used to transport multiple heads of state off of a peninsula after high level discussions. I assume this was due to some security consideration, but I don't know. The crowd was passive.
If the lawful order was give, was it because criminals were using the peaceful protest as cover?