May I introduce a bit of reality here? Children are no more likely to be kidnapped and murdered now than they were fifty years ago, at least not in the USA. In fact, they have a better chance of being struck by lightning.
As for the number one killer of American children, that would be vehicular accidents. Yep. That's right. Statistically, those children who walk two blocks or two miles are safer than those who are driven two blocks or two miles.