After the murders of 10-year-old Soham girls Holly Wells and Jessica Chapman by Ian Huntley, their school caretaker in 2002, the Government said it would tighten checks.
Last year Ruth Kelly, then education secretary, was embarrassed by the revelation that 88 sex offenders had been working in schools despite the safeguards. From next year, the education department will help run a new vetting regime with 10 million personal histories. But critics fear offenders will continue to slip through the net.
Photograph: Rex Features