(Assuming there's some good faith there.)
Governments ought not to "control" protest crowds in a democracy. This is literally written down in the foundational-myth-papyrus of America.
By and large none of these crowds start as "violent" crowds. These are drivers, bartenders, moms, students, butterfly-collectors, tinkerers, teachers, short-order cooks -- they are citizens, calling for a redress of grievances.
The instinct and assumption that you ought "correctly to control" such people is what leads to increased tension and ultimately violence.
Source: I live in Seattle, and for nearly 10 years lived a block off of Pine St. (almost all of the pictures or videos you have seen of Seattle recently would be on the Pike/Pine corridor). I would see protest marches off my porch and on my walk to work, as well as black bloc types. I've walked home on May Day through protests a few times. The participants all start very clearly as protesters or vandals. Protesters have signs and wear their union jackets or their scrubs or their tennis shoes and khakis, or their superhero outfits, or whatever; they are there to protest. There are very, very few proper vandals to start off these things.
But you know what vandals and looters love? The chaos that ensues when forces with an instinct to "control" unleash munitions and other uses of force on the protesters. Do some protesters boil over and turn into vandals when the temperature and pressure turn up? Yes.
By the time you have a "violent crowd", you've fucked up and arguably lost the mandate of heaven.
Do you live in a metropolitan city in the US? Seattle, USA is my point of reference. I have lived for 15 years here, mostly living in the most dense neighborhood and mostly working in the downtown core.
Seattle is a low-violence, high-civic-engagement, high-trust, relatively wealthy city. There is typically a small 10-50 person protest weekly in front of the Federal Building. There will be additional larger protests several times annually, with a 200-500+ person gathering probably about every two months in favor of pot, anti-war, or whatever. Then 2-3 times a year there will be a large gathering, often around May Day, MLK Day, Hempfest, etc., where thousands will gather for (generally permitted and pre-planned) marching and demonstration. This is all the baseline activity level regardless of things like COVID, Trumpism, or BLM.
It's very usual to see strollers and children on shoulders at these events. The strong presumption is that civic engagement in Seattle is safe and normal.
If you come from a place where political parties have proxy street-fights with backed youth gangs, or where ethnic mobs are torching trains full of apostates, I understand (and I'm very sorry and hope it gets better). I know the world is a scary place and that there are such things as violent mobs.
But despite how inconvenient it might be to have one's commute path blocked, or how scary it might initially be to have an Other-looking youth shouting hyperbolic slogans, protests here (and elsewhere) generally don't start, and don't inevitably turn, violent.
That particular reaction requires another reagent altogether, and usually quite a bit of activation energy.
If you write a firmly worded letter to your Senator, you are protesting and it would take the most abusive stretch of discretion to consider it criminal in any way.
If you drive with your buddies in dark of night to a store and do a smash-and-grab, it would take an absurd ideological contortion to consider it protesting in any genuine way.
In real life, there's a spectrum moving from letter-writing and sign-holding into civil disobedience and then into forms of disorder.
If you start with the observation, as you have, that "people are taking this opportunity to steal and ... burn[] down shops," I would submit that you shouldn't then apply the term "protester" to what you are defining as an opportunistic criminal.
You know what has worked really well for Niketown in Seattle the last few days? They just have a bunch of beefy dudes in athletic wear (some Polynesian fella cheered them as being Samoans, I dunno, but it's relevant mainly in that they look not like a bussed-in white-only goon squad, and optics are gonna matter in this crisis) standing around it. Nobody's messing with those guys.
If your cops aren't up-armored and manning a barricade of people doing free speech stuff, they can, you know, take 911 calls and go respond to actual calls.
I would challenge your insinuation that theft and arson are "in places where the police [are] weak" and the implicit corollary that you should then make those police more "strong." I would grant you that (perhaps tautologically) those crimes happened in places where keeping the peace has been done poorly, and it should be done better.