Oh, I hate it when the only image I can find of a book has that "Search Inside" thing from Amazon!
Anyway, Joel Best's Threatened Children: Rhetoric and Concern about Child-Victims is an EXCELLENT and thorough analysis of the way issues around children are constructed. It covers missing children, child molestation, and urban legends such as Halloween sadists. It looks at how claims-makers operate and explores the way secondary claims-makers, such as network news and popular culture amplify and distort these claims. Importantly, he points to the fact that individual deviants are always identified as the problem, not larger social factors... Also, he addresses the fact that even when momentum dies down, many of these campaigns leave legacies and can become entrenched taken-for-granted ideas in the general public.
My only wish is that he had written this more recently! I have my work cut out, having to update his information!