1) Keep in mind that there will always be someone who is liked the least. Think carefully about whether this person is destructive enough to be worth the reaction.
2) How severe your reaction should be depends on how dangerous this person is. In most cases, shunning might be enough. If they steal or endanger others, then for the sake of your own conscience, make sure they are actually in the act before you pull the trigger.
3) Whenever possible, follow basic guidelines of justice. A hearing, a trial, a decision made by the community.
I don’t know your exact situation, so I’m afraid I can’t get more specific than that.
Our block is a really safe block, most everyone knows each other and get along well. We all help each other out and do things for each other. Except for the one family, that happens to be next door to me. Father is a loud-mouthed loser, long divorced with three adult daughters, only one is decent. The other two daughters have drifted away and back multiple times, and are currently living there, each with their own kids. The two daughters don't work, receive welfare and have their own kids there from multiple dads. They all smoke and drink heavily, and have indulged in drugs (at one point selling them from their home). When I've found liquor bottles on my lawn, I break them at their doorstep and that stops that. Cops have come out multiple times, only and always to their house for domestic fighting, a couple times arrests happened. Dad doesn't maintain the grounds, weed-infested and poorly maintained with paint that looks like graffiti. Getting the picture of my situation?
I and my other neighbors have called the cops in the past because of a black boyfriend stumbling down the block drunk while punching on cars. Or another boyfriend on drugs in the back yard at 3 am screaming his head off. Currently social workers are frequenting the house almost daily because of family fighting with the kids involved, a couple times they were removed from the home.
I have had quite a few arguments with the dad over things they have done, and more or less told him I will exact revenge the next time they get out of line doing something to my property. He has also had confrontations with the other neighbor on the other side of his house, the other neighbor pretty much said the same thing to the dad between us. Not only that, my other neighbor is a security guard so the two of us are armed and the bad dad knows that. If the SHTF, we can handle him.