Sex offenders who were "outed" were more likely than those retaining anonymity to commit further crimes after their release. The findings, which are being considered by the Home Office, suggest that mob fury fails to make any contribution to preventing re-offences.
Opponents of the identification of sex offenders say the report demonstrates that telling the public does not reduce the number of sex crimes and could instead disrupt police supervision and force offenders underground.
The American research shows about one in five convicted sex offenders later commit other sex attacks. The figure was slightly higher for unidentified offenders (22 per cent) than for those who had been "named and shamed" (19 per cent). But the Home Office claims that the difference is "statistically insignificant".
The research, by an urban policy group in Seattle, tracked 139 sex offenders - 125 adults and 14 juveniles - released from prisons in Washington State between 1990 and 1993. It compared the re-offending patterns of those subject to "community notification law" and those who were released before the law was introduced.
Four-and-a-half years after their release, 57 per cent of publicly identified sex offenders had been arrested for some kind of criminal behaviour, as opposed to 47 per cent of those whose identities were kept under wraps.
The named sex offenders were, on average, arrested again in two years for other offences. But it took an average of five years for those who remained anonymous to be arrested for fresh offences.
The report suggested, however, that offenders who were publicly identified when released were subject to greater police targeting and surveillance.
"The American experience shows that telling the public the whereabouts of individual offenders does not reduce the number of sex crimes," said Paul Cavadino, director of policy and information at the National Association for the Care and Resettlement of Offenders.
"Community notification would add nothing to public protection. It can also produce a false sense of security by diverting attention from other paedophiles and potential offenders who have not been convicted."
Nacro, which tomorrow will release a report on reducing the risk from sex offenders, believes the police register of offenders' names and addresses helps police and the probation service with their surveillance. "The evidence shows that extended post-release supervision of offenders and more treatment programmes would do far more to protect the public than American-style community notification," Mr Cavadino said.
The issue of whether the identification of sex offenders protects the public, particularly children, has raged since the release of two paedophiles, Sidney Cooke and Robert Oliver, who recently accepted voluntary restrictions because they feared for their safety.
Last month, a paedophile had to change plans for returning to his home in the Oxfordshire village where one of his victims still lives. Rhys Hughes, who was sentenced to 10 years in 1992 for the rape and buggery of nine children, eventually agreed to move to accommodation away from his home in Sonning Common after being warned that he might face vigilante attacks.
The Association of Chief Officers of Probation has identified 40 cases where the "outing" of sex offenders led to vigilante action or offenders going to ground, disrupting supervision and surveillance arrangements. The association warned that such action, stirred up by media attention, could be counter-productive and called for supervised accommodation and efforts to persuade offenders to agree to voluntary supervision and treatment.
"We don't object to the public being informed in certain cases but the priority has to be the protection of the public," a spokeswoman said. "If a paedophile sex offender has been released, we won't name him if we think public safety will be jeopardised. That could happen if he goes underground and the authorities lose track of him."
The Home Office accepts that "outing" does not reduce the chances of paedophiles re-offending. A spokeswoman said: "It's not as simple as telling people that a paedophile is in their neighbourhood. It's up to the local police if they feel it's in the public's best interests to identify a paedophile, but we feel it's not generally useful. It's better if the person is targeted and supervised by police and the Probation Service."Reuse content