Perhaps there’s some misunderstanding.
Neither orderly, civil disobedient, nor violent protests will stop anything completely. Police will always kill unjustly, because police are comprised of hundreds of thousands of individuals with human frailties and faults, drawn to a job which requires them to carry a gun and the potential to shoot at “bad dudes.” To think that wouldn’t involve at least a few people with the necessary personality components required to become racist murderers is kind of naive.
However, any claim that protests “don’t work” is to accept the notion that everything short of perfection is an equivalent failure. I get the “One death is one too many” concept, but frankly it’s a misplaced application of that philosophy. There are degrees of failure - ranging between one unjustified questioning and the systematic deaths of millions - and therefore there are degrees at how effective or not protests can be.
To go around and say that protests don’t work is to dismiss their effectiveness, and they ARE effective at promoting change - slow and unsteady, but still change. You have to imagine what the world would be without them, and then measure the difference between that and our reality. If “protests don’t work” becomes a popular refrain, it discourages those who might partake. Even if it’s “orderly, peaceful protests don’t work” then that still disenfranchises those who can’t risk anything more extreme and yet still can make their voices heard. That only helps those who would strive to keep the status quo.
That said, MLK was not always partaking in orderly protests and complying with the cops. He broke laws and inconvenienced innocent people by way of protest, as did a great many others in the 50’s and 60’s. So did Vietnam protesters. Both groups helped push change, and I think one could successfully argue that pissing off people helped to highlight the situation. It’s kind of like “saturation marketing,” if you’re thinking of a marketing metaphor. Companies want people to be aware of their names first, even if it’s from a really annoying character or jingle, and then they can worry about balancing it out later.