Wolf in the Hen House?

Today I had one of those moments that probably a lot of people across middle-class America have had at point or another, or will have at some point in the future. The realization that "That can't happen here" most certainly can. It seems as though we're about to get a new addition to our neighborhood, and it seems as though he's not going to get the warm welcome most new residents to our quiet, tree lined street typically get. You see, our prospective neighbor happens to be a registered sex offender, and it's quite disconcerting. I don't know the details, and I suspect there won't be much of an opportunity to learn the details, I'm not sure it matters a great deal one way or the other. Fact of the matter is that he was convicted, he served time (in Florida) and that he's recently registered with the Pennsylvania State Police, which is how we found out about him, via the Meagan's Law website that the state operates.
I don't know a great deal about the people he is to live with, other than that I now take their morals & values into question, as well as their use of common sense. Folks, this neighborhood is teeming with children. What kind of person of good conscience and mind would permit a relation or a friend who has a record and history of sex offense(s) against minors to reside with them?
I suppose that all I can do is be hyper-vigilant, keep an eagle eye out on my kids and every other child in this neighborhood and to teach my two children about strangers, hopefully not scaring them in the process, and hope that it's enough. Tomorrow, my sister is canvassing the neighborhood with this guy's stats and a pic, which will likely not be a popular move, but it's vital that everybody here be aware of what is about to happen.
Our neighborhood here is a little slice of heaven. Brick houses, some lovely old walnut trees here and there, the type of street where everybody knows everybody. Kids and grandkids playing in yards, backyard pool parties in the summer, a neighbor with a snow plow and another with a snowblower clearing the street and sidewalks in the winter after a snowstorm blows through. Block parties, trick or treating, laundry drying in the breeze. You can still borrow an egg or a cup of sugar from your next door neighbor here. It's not some throbbing metropolis. Many people leave their doors unlocked and their car keys in the ignition, or, if they're concerned about car theft, they'll throw their keys under the seat, or tuck them under the visor. So you hear sex offender and immediately, all those worry-free liberties you once cherised and felt okay with doing don't feel so safe any more.
Yeah, there have always been perverts, and there always will be perverts. And I should be thankful that this particular one decided to follow conditions of his parole and actually registered. Thankful, but wary. I'll update when I know more info.