In the mid-1990s, Megan's Law was introduced in the US after the murder of seven-year-old Megan Kanko by a sex offender who had moved in across the street.
The case of Craig Sweeney saw renewed calls for 'Sarah's Law'
That law gives parents access to information on paedophiles living in their community.
In Britain, there has been a campaign for equivalent legislation, dubbed 'Sarah's Law' by proponents after another young victim, Sarah Payne.
But now the government has rejected those demands, ruling out any kind of public access to the sex offenders' register.
Instead, only parents and guardians will be able to request information on specific individuals who may have unsupervised access to their children, such as new partners joining a single parent household.
The decision will come as a disappointment to Sarah's parents, Sara and Michael, and to the News of the World newspaper which has championed their call for a change in the law.
When eight-year-old Sarah was killed in 2000 there was widespread public grief.
But that sentiment turned to outrage when it emerged that the culprit was a known paedophile - Roy Whiting.
He had been jailed in 1995 for kidnapping and indecently assaulting a nine-year-old girl and placed on the sex offenders' register.
But his behaviour remained unchanged - with terrible consequences.
In July 2000, the News of the World published the names and photographs of 50 people it claimed had committed child sex offences and pledged to carry on until it had "named and shamed" every paedophile in Britain.
The editors said they were "taking action for Sarah and for all the other little victims".
The campaign certainly struck a chord, but it also backfired, leading to violence, vigilantism and mistaken identity.
On the Paulsgrove estate in Portsmouth, protesters - mostly mothers and children - took to the streets every night for almost a week, waving placards saying "Kill the paedophiles".
Cars were torched, windows smashed and at least five families were forced out of their homes after becoming targets.
Elsewhere, two men suspected of being child sex offenders committed suicide and in Newport, Gwent, paediatrician Yvette Cloete came home to find her front door daubed with graffiti branding her a paedophile.
Someone had misunderstood her job title.
Senior police officers eventually spoke out fearing there would be a murder.
Right to know
The paper then began demanding Sarah's Law instead, backed by her anguished family who were adamant that had they known Whiting's whereabouts they could have kept their daughter safe.
The Paynes felt that if they had lived in the US - with Megan's Law - Sarah would still be alive.
Initially, the government appeared keen to follow the US lead, saying it would make "urgent and serious consideration of the demands".
But criticism from criminologists, probation officers and the Association of Chief Police Officers prompted a rethink.
Those critics pointed to vigilantism in the US and suggested that greater public knowledge actually drives offenders underground and makes them harder to monitor.
Eventually, Home Office minister Beverly Hughes turned down 'Sarah's Law', insisting: "We're clear that it won't help to protect children."
Instead, the government brought in other new measures in 2001, among them the requirement for sex offenders to register with their local police station within 72 hours of being released from prison.
The law also created Mappa - multi-agency public protection arrangements - which were designed to involve police, probation, charities and other bodies to closely monitor dangerous offenders.
These were not foolproof and calls for a 'Sarah's Law' resurfaced when several child sex offenders, including Craig Sweeney, slipped through the net.
Sarah Payne was abducted in Kingston Gore, West Sussex
In January 2006, Sweeney kidnapped and sexually abused a three year-old-girl, despite theoretically being subject to Mappa.
His victim's mother said if Sarah's Law had allowed her to know of his past, he would never have been allowed to go near her daughter.
Soon after, pressure on the government increased again when the News of the World revealed that 60 paedophiles had been housed, with official approval, at sites near schools.
Home Secretary John Reid then made the surprise announcement that the Home Office would consider Megan's Law after all and would send a minister to the US to see it in operation.
Gerry Sutcliffe travelled to New Jersey and met with Megan's parents, but later said it might not be possible to transpose the legislation to the UK because of different "structures".
Then, in November last year, the newly created Child Exploitation and Online Protection centre took the unprecedented step of naming missing paedophiles on its website.
It also asked the public for help to locate them.
In January, Mr Reid said lie detector tests would be introduced to help keep track of offenders.
The announcement came as the News of the World revealed that police forces across the UK had lost track of the whereabouts of 322 convicted sex offenders.