The Supreme Court yesterday strongly backed Megan's Laws -- which provide the public with information about potential sexual predators -- ruling in two cases that they do not violate the individual rights of convicted sex offenders.

The court ruled 9 to 0 that Connecticut may publish the names, pictures and other information about convicted sex offenders on the World Wide Web without giving each offender a hearing to determine whether he or she is still dangerous. By a vote of 6 to 3, the court ruled that Alaska's law creates a civil regulatory system to protect public safety -- not punishment on top of the sentences that ex-offenders have already served.

"[T]he fact that [a sex offender] seeks to prove -- that he is not currently dangerous -- is of no consequence under Connecticut's law," Chief Justice William H. Rehnquist wrote in the opinion for the court in the Connecticut case. He noted that the state, on its Web site, includes a disclaimer that it does not necessarily believe each individual listed is dangerous.

"Our system does not treat dissemination of truthful information in furtherance of a legitimate governmental objective as punishment," Justice Anthony M. Kennedy wrote for the court in the Alaska case.

The ruling is the first from the Supreme Court on the highly popular Megan's Laws -- which are on the books in all 50 states and the District -- against what had been an increasingly successful effort by civil libertarians and criminal defense lawyers to scale back their impact.

Connecticut's Web site has been blocked since 2001, when a federal district judge ruled that the state's law violated the constitutional guarantee of due process because it did not afford sex offenders a hearing before posting their names. That ruling was upheld by the U.S. Court of Appeals for the 2nd Circuit.

The Alaska law was struck down in 2001 by the San Francisco-based U.S. Court of Appeals for the 9th Circuit. It ruled that the law had a punitive effect on sex offenders, and therefore violated the Constitution's ban on ex post facto laws because it increased offenders' punishment after they had served their sentences.

In 2001, U.S. District Judge Ellen S. Huvelle invalidated the District of Columbia's provisions for public disclosure of offenders' information, giving reasons similar to those of the 2nd Circuit in the Connecticut case. But that ruling was stayed, allowing the registry to continue operating. The case, now before the U.S. Court of Appeals for the D.C. Circuit, has been awaiting the Supreme Court's decisions in the Connecticut and Alaska cases.

Roscoe C. Howard Jr., the U.S. attorney for the District, said he was pleased with today's ruling, "so that the public can be fully informed about sex offenders in the District of Columbia." There is no timetable on when the appeals court would take up the case.

Another challenge to the law on appeal in D.C. Superior Court has also been stayed pending the Supreme Court's decision. Trial judges in that court have upheld the law.

Connecticut Attorney General Richard Blumenthal called yesterday's ruling "a victory for children against the continuing, serious threat of sex offenders." He said that he will put the state's sex registry back online as soon as possible.

"It's disappointing," Joshua Dratel of the National Association of Criminal Defense Lawyers said of the ruling. "These lawsuits were designed to introduce some fairness into the designation process."

Megan's Laws are named for Megan Kanka, 7, who was raped and murdered in 1994 by a neighbor in New Jersey. Unbeknownst to her parents, he was a convicted child molester.

Within two years, all the states and the District had enacted some version of a Megan's Law, spurred in part by a federal statute conditioning law enforcement aid on the adoption of such laws.

The Connecticut statute at issue yesterday requires all people in the state who have been convicted of certain crimes -- most of which are sex-related -- to supply their names, addresses, photographs and DNA samples to the state police, and then update the information regularly.

In a concurring opinion yesterday, Justices David H. Souter and Ruth Bader Ginsburg said the Connecticut law might be open to a different constitutional challenge, on the grounds that it may unfairly exempt certain offenders, such as 18-year-olds convicted of having sex with minors between the ages of 13 and 16.

The Alaska law requires any sex offender or child kidnapper in the state to provide quarterly updates on his or her address, physical description, license plate number and other information for 15 years after leaving jail. Offenders convicted of an aggravated offense or more than one offense must submit the information for life.

The unnamed sex offenders who sued the state in this case contended that the law was a punishment because it imposed onerous reporting requirements and made it harder to get or keep a job. It violated the rights of people such as themselves, who had been convicted before the law even took effect, they maintained.

Dissenting from the Alaska ruling, Ginsburg, with Justice Stephen G. Breyer and Justice John Paul Stevens, writing separately, said the law was a form of punishment.

Ginsburg likened it to "shaming punishments once used to mark an offender as someone to be shunned." She noted that one sex offender in the case had been rehabilitated and granted custody of a minor child, but must still register for life.

Kennedy countered that the state's Web site "does not provide the public with any means to shame the offender by, say, posting comments underneath his record." He noted that "the record in this case contains no evidence that the Act has led to substantial occupational or housing disadvantages for former sex offenders that would have not otherwise occurred."

The cases are Connecticut Dept. of Public Safety v. Doe, No. 01-1231, and Smith v. Doe, No. 01-729.

Staff writer Neely Tucker contributed to this report.

Chief Justice William H. Rehnquist, left, and Justice Anthony M. Kennedy said that the two state laws in question did not constitute additional punishment.