My comment is this: Generally and overwhelmingly, when a group of people is more interconnected and those connections are stronger, "bad" behavior gets found out and stopped faster. I think that's true of any group of people.
Of course, "bad" = unacceptable to the group itself.
Someone telling you "I did this bad thing" is not the only way for you to find out. I think if a child knows there is a way out, that there other people who care enough to take effective action, they might be more likely to tell someone. But often there is no one who cares that much. Teachers, neighbors, other parents, they're all "nice" but they aren't invested.
What I'm talking about is a deep relationship, and that isn't a function of time spent together, or any other concrete fact. It's organic and emotional.
We can grow those relationships if we choose to. I feel this is the only way to actually solve a lot of social problems that have been going on for decades now. Shooters, internet trolling, bullying, abuse, molestation, those people who pop up every year or so who have been hiding 15 children in a basement..etc