Due to presumed low rehabilitation rates for sex offenders, many registries and community notification provisions apply retroactively to offenders who committed their crimes prior to the enactment of laws. In several States, however, the retroactive application of laws has encountered legal challenges and has resulted in the suspension and subsequent revision of some laws. A survey of sex offender registry laws found that 22 States retroactively apply their laws. Legal challenges are pending in four (Alaska, Louisiana, Minnesota, and New Jersey), and South Dakota is anticipating challenges. Of the six States without sex offender registries (Hawaii, Massachusetts, Nebraska, North Carolina, Pennsylvania, and Vermont), legislation to establish such registries has been introduced in Massachusetts, North Carolina, and Pennsylvania. New York's sex offender registry statute, passed in May 1995, is briefly described.