That's just hiring someone else to use force to take it back. So we at least agree that taking it back by force is the right thing to do. I'll even go so far as agreeing with you that it's morally justified to hire someone else to do it for you. I suspect our area of disagreement is really narrow on this issue.
Yes, there are often police who do not follow the regulations on how to interact with suspects, but I believe it is better to have guidelines which are sometimes broken than none at all.
edit: changed vigilantes to mercenaries for consistency
I'd say it's a toss-up if I absolutely had to guess.
We literally cannot remove the police without a collapse of the state and consequently the rest of our civilization, and if you think for even one moment about how that would play out it would be apparent: everything fractures into private armies with no incentive to uphold democratic rule of law; the most powerful private armies become de facto states and their ruler a law unto himself--effectively a king. Obviously modern society can't survive under these conditions--no one can trust rule of law which absolutely underpins our economy. So congratulations, you've rediscovered the dark ages and doomed hundreds of millions to deaths from violence, illness, and starvation. :)