But you're still missing the point @Hertsgirl10
Kidnapping children is incredibly rare. Whilst it's terrible these things happen,and yes 1 case is too many, the real risk comes from the trusted adult...the parents,the siblings, the extended family, the teacher, the activity leader etc.
And by "knowing" that they love down the road, means innocent people get attacked, it doesn't stop them being a paedophile, or doesn't protect your children, it serves very little purpose.
It's a bit like knowing that your neighbour is a convicted and serial burgler. You, in theory, are already locking doors, making things secure, expensive things out if view etc. What .orenare you going to do, that you wouldn't be doing already?
I know it's not the same level of seriousness,but honestly, what will "knowing" do for you?
How will you know 100% that they are a what Sally down the road has told you? She heard it from where?