Police doubt 'Sarah's Law' will cause vigilante attacks
Police have played down fears that allowing parents to check if someone with access to their children is a sex offender may cause vigilante attacks.
The scheme known as "Sarah's Law" was proposed after the murder of eight-year-old Sarah Payne 10 years ago.
A Home Office pilot is being extended to eight more forces in England.
Chief Constable Paul West of the Association of Chief Police Officers said it was "realistic" to think people would keep information to themselves.
The scheme was piloted in four areas in England from September 2008 and will be expanded to the whole of England and Wales by spring.
Sarah was kidnapped and murdered by a convicted sex offender, Roy Whiting, in West Sussex in 2000.
Charities have warned the scheme could backfire by driving paedophiles underground.
Diana Sutton, of the NSPCC, said it was good that the pilot schemes had helped protect some children, but urged the government to "tread cautiously" as it expanded the initiative.
"We remain concerned about the risk of vigilante action and sex offenders going underground. All new local schemes need close management and proper resourcing to avoid this," she said.
But Chief Constable West said people would not need to share the information as police would inform any affected party.
"If there is information that says someone with previous offences for child sex offending is living in a particular house next door, and became known to a person, if there were other children to whom they have access, clearly that would come out in the course of the investigation and we would disclose that appropriately to anyone who has children who are at risk," he said.
"The point is, we don't go for widespread public disclosure to anybody and everybody because that's just the sort of thing that leads to the vigilantism which we've seen in the past."
And Sir Hugh Orde, president of the Association of Chief Police Officers (Acpo), said there were always risks.
"People say people will go underground - frankly, people go underground anyway.
"With all the other parts of the police service working also in this area, I do think we have got a real hope of keeping people safer and keeping young people safer, which is very important."
'Sarah would be proud'
Home Secretary Theresa May said the expansion of the scheme was an "important step forward for child protection" which would also help police manage known sex offenders more effectively.
"Being able to make these checks reassures parents and the community and, more importantly, keeps children safer," she said.
The original trial of the Child Sex Offender Disclosure Scheme took place in Cambridgeshire, Cleveland, Hampshire and Warwickshire.
The Home Office said more than 60 children had been protected from abuse during the pilot scheme.
Nearly 600 inquiries to the four forces involved in the pilot led to 315 applications for information and 21 disclosures about registered child sex offenders.
A further 43 cases led to other actions, including referrals to children's social care, and 11 general disclosures were made regarding protection issues linked to violent offending, they said.
The scheme is now being rolled out to eight other force areas - West Mercia, Bedfordshire, Norfolk, North Yorkshire, Thames Valley, West Midlands, Essex and Suffolk.
A further expansion is planned for the autumn, with Northamptonshire, Staffordshire, Sussex, Leicestershire, Wiltshire, Cheshire, Durham, Northumbria, Dorset, Lincolnshire, Surrey and Gloucestershire joining the scheme.
It will be rolled out to other forces by spring next year.
A similar extension of a pilot scheme was also proposed for Scotland earlier this year. Northern Ireland is yet to decide whether to implement a scheme.
Sarah Payne's mother, Sara, was made the government's Victims' Champion after her campaign to bring in the measures.
She wrote in the News of the World newspaper that "despite this positive step, I still believe there's a need for fuller disclosure".
But she said children had been made safer, adding: "Sarah would be so proud, I'm only sorry it took her death for this vital reform to become a reality."
One father living in a pilot area told the BBC he faced a dilemma when he discovered the background of a man who worked at an outdoor facility his daughter used.
"I made a very swift decision that my daughter was never going back to that facility again, and had to decide, 'should I tell other parents or keep it to myself?'
"I have, to this day, kept quiet on it really and I'm still not sure whether I should alert them, but it's a very difficult situation to be in," he said.
The so-called Megan's Law in the US, which allows the publication of names, addresses and pictures of paedophiles in some states, prompted calls for an equivalent "Sarah's Law" in the UK.