"Well, we've got them all enlisted in the military - maybe there's a civilian equivalent? A humanitarian relief corps or something, just something that gets everyone during young adulthood working alongside people from different cultural backgrounds and in a clear and well-defined command structure where their officers can get to know them - most human crime is concentrated in men aged sixteen to thirty, you can very nearly vanish it just by keeping them occupied during that time period. Wouldn't even have to be mandatory, just very generously compensated.
Then if, say, someone is beating his wife, she can go to her commanding officer and they can investigate, sit him down and figure out what's going on and warn him he's endangering his status, if necessary transfer him across the continent -"