The impulse to post the names, pictures and locations of sex offenders on public registries is understandable. That doesn't make it smart, or right. Rather than continuing efforts to showcase or expand online registries, political leaders should take a genuinely courageous step and shut them down.

Aside from murder, no crimes are more repugnant than rape, child molestation and other forms of sexual assault. Sex offenders deserve criminal punishment and social reprobation. In many cases, no amount of jail time can repair the damage they do to victims, families and communities.

The entire premise of public registries, however, is wrong. While supporters say they give people an important tool to prevent sexual abuse, the facts suggest they provide an illusion of safety — and may, in fact, make offenders more likely to commit new crimes by consigning them to social isolation.

When murderers, armed robbers and other criminals do their prison time, they are considered to have paid their debt and are allowed to re-enter society without being listed on a registry. Not so sex offenders. In New Hampshire, all offenders convicted of sexually abusing children find their names, pictures and addresses posted to a state Web site when they return to the community. In Vermont, a smaller group of high-risk offenders is posted (with towns, not specific street addresses), although lawmakers may double that list's size.

Supporters of registries argue that the public needs to know about predatory strangers moving in nearby. Also, sex offenders will inevitably seek out new victims, they say. Both arguments hold great emotional and political appeal.

Neither is backed by the facts.

Sex offenders are almost never strangers to their victims. According to a Valley News analysis of statistics and studies, at least 97 percent of sex offenders in both states were relatives, friends or acquaintances of their victims. In other words, most victims and their families didn't need to fear a predator lurking in the shadows; the abuser had a familiar face.

And while politicians have tried to score political points by asserting that sex offenders almost invariably reoffend, the facts again contradict that claim. While some hard-core offenders have alarming recidivism rates, experts say that the most common type of sex criminal — one who grooms a victim known to him — is far less likely to reoffend once returned to a now-vigilant circle of family and friends. Further, sex criminals who undergo treatment reoffend at sharply lower rates.

Even as offender registries fail to live up to their justification, they can create new risks. The most dramatic is vigilantism, a point illustrated most recently in Maine, where Stephen Marshall looked up the addresses of two sex offenders and shot them dead. There have been other instances of vigilante justice, some close to home: A man mistaken for his sex-offender brother was nearly beaten to death with a baseball bat in New Jersey, the state that began the nationwide move to Internet registries after 7-year-old Megan Kanka was killed by a neighbor. A New Hampshire man stabbed a man and lit fires in two buildings in Concord occupied by convicted sex offenders. Last May in Lebanon, a man knocked on the door of a registered sex offender and punched him in the face.

A more insidious problem is ostracism. Even with the harsher sentences now under consideration in New Hampshire and Vermont, most offenders eventually will return to our communities. When they do, the odds of them leading productive lives will depend on their ability to find jobs, reunite with family and friends, and win a place in society.

That goal is thwarted by the public registries. In recent weeks, two high-profile offenders have emerged from prison and returned to the Upper Valley, only to find themselves shunned. To be sure, Thomas Pellerin and Leon Colbeth have earned a measure of enmity and fear; they not only committed sexual assaults but also failed to participate in treatment programs while in prison. But what are the odds of them becoming law-abiding members of the community if nobody will afford them a peaceful place to live and work?

Rather than using public registries to create a new form of scarlet letter, officials would do well to focus on the traditional way of keeping tabs on potentially dangerous criminals — sharing their names with local police officials and conducting criminal background checks for those applying for jobs involving children or other vulnerable people.

Another productive approach would be to follow the lead of the Upper Valley's Women's Information Service (WISE) in helping to educate children and adults about how to respond when someone — stranger, relative or friend — crosses the line. No system, public or private, can eliminate all risks. But a heightened awareness can significantly reduce them.

If New Hampshire Gov. John Lynch, Vermont Gov. Jim Douglas and other political leaders want to do more than simply score cheap political points in an election year, they should use their bully pulpits to inform the public about the real risks of sex offenders — and the frightening consequences of banishing them to the fringes.