It goes back to Soham where school caretaker Ian Huntley murdered schoolgirls Holly Wells and Jessica Chapman, and to the dilatory Criminal Records Bureau checks on teachers applying for jobs. Indeed, if CRB was working properly none of the latest problems over List 99 might have arisen.
Every time there is an outcry by the press and public, politicians head off criticism with short sharp legislation or official inquiries. And as night follows day, tardiness after the inquiry lands future ministers in hot water.
The latest example is former education secretary Charles Clarke's failure to implement key recommendations of the Bichard inquiry into Soham on grounds of cost. Had Bichard been acted on more speedily and a central list of people banned from working with children created, Ms Kelly would not be in such a mess. Now, the Government's hand has been forced and more recommendations will be pushed through.
What happens now? One rule must apply, summed-up by Chris Keates, general secretary of NASUWT: "Abusers have no place working with children." Risks posed by pupils who are themselves abusers also need urgent consideration, as our page 1 story shows.
The sooner ministers are stripped of powers to sanction appointments the better. It is an unnecessary power - irrelevant when it works and damning when it fails. This should be the work of experts, under jurisdiction of Ms Kelly's department but outside it. The present system needs replacing with one giving schools instant access to online checks. But it will need regular monitoring to guard against teachers being wrongly accused or paedophile witch-hunts. Teachers will be nervous about a rising tide of accusations.
But they will accept, unlike some hysterical commentators, that the most important issue is the protection of children not the hounding of Ruth Kelly.