A security system that screens for registered sex offenders or those involved in custody disputes is being tested by Adams 12 Five Star Schools in Colorado. The system caught one sex offender trying to pick up a child at Rocky Top Middle School last year. Instead of armed guards, every visitor to four schools is greeted by a smiling school receptionist who swipes a driver's license through a card reader. The visitor's name is screened against registered sex offenders across the country. If a name matches the registry, an alert goes out to school security personnel and the person is detained.