BERKELEY, Calif. (AP) — The California Supreme Court heard arguments Tuesday in a case filed by four registered sex offenders who claimed they would be forced into homelessness were the justices to allow the state to enforce Jessica's Law.

That voter-approved measure bans them from living within 2,000 feet of a school or park, a provision that had since been suspended pending the outcome of the case.

Justices must determine if the residency requirements of Proposition 83, the Sexual Predator Punishment and Control Act passed in 2006, violates the constitutional rights of the offenders.

The court's ruling could affect not just the four offenders, but also determine whether thousands of paroled registered sex offenders would have to find new homes.

At least one member of the panel, Justice Joyce Kennard, appeared to question the success of residency restrictions in doing what Jessica's Law was designed to do: protect children from sex criminals.

"(Registered sex offenders) can still mingle out there, they just can't live out there," she said, referring to parks and other places children regularly congregate.

Jessica's Law mandates that all registered sex offenders paroled after November 8, 2006 — when the law took effect — comply with the 2,000-foot rule or risk having parole revoked and a new prison term.

However, the law does not apply to all of state's registered sex offenders, such as Phillip Garrido, who is accused of the kidnap and rape of Jaycee Lee Dugard. His parole in an earlier rape case predated the law by more than a decade.

The four plaintiffs argue the court should throw out Jessica's Law's residency requirement because it violates their constitutional rights by making the parole terms unreasonable by taking the state's major cities off-limits. They argue that the state has defined where they cannot live but provides no help finding them new housing that does not violate the law.

"For one client, his only recourse is homelessness, which inevitably leads back to jail," said plaintiff attorney Ernest Galvan.

Even though the plaintiffs' post-2006 parole terms were not for a sex-related crime, they were already registered sex offenders, which put them under the Jessica's Law umbrella. The court will decide whether Jessica's Law would apply to people whose sex crime convictions and parole terms occurred years before the law was passed.

Gov. Arnold Schwarzenegger and corrections officials are defending the law, saying it does protect children.

Voters passed the law, which promised to create "predator-free zones" where registered sex offenders would be kept away from places where children congregate.

"The purposes that motivated voters was the desire to protect their communities and their children from the risk of recidivism that convicted sex offenders pose," said Kenneth Mennemeier, a lawyer for the state Department of Corrections and Rehabilitation.