Mount Kisco isn’t “wealthy” in the way Bedford and Chappaqua are. While Kisco has a number of fairly affluent areas (although not as wealthy as Chappaqua or Bedford), the other half of the town is filled with housing projects (which get periodic drug raids) and dilapidated slums that pack unsafe numbers of illegals and/or their families into small spaces. Periodically ICE or local authorities have targeted an apartment or two, but the illegal problem persists because people STILL hire them in the area. It’s still not as bad as Peekskill or Brewster (or Port Chester or Mamaroneck) but I would say the town ranks high as being a hotspot for illegals.
As a former resident, I can attest to the problem with illegals. Occasionally I would find their garbage littering the woods near my house (many of them are homeless and take the liberty of sleeping in Leonard Park and in small wooded areas on private property!)
Actually, the worst towns period in Taxchester are Mount Vermin and Yonkers.