A sex offender registry is a system in various countries designed to allow government authorities to keep track of the residence and activities of sex offenders, including those who have completed their criminal sentences.
In some jurisdictions in the United States, where sex offender registration began, registration is accompanied by residential address notification requirements.
In many jurisdictions, registered sex offenders are subject to additional restrictions, including on housing.
Sometimes, these include (or have been proposed to include) restrictions on being in the presence of minors, living in proximity to a school or day care center, owning toys or other items of interest to minors, or using the Internet.
Sex offender registries exist in many English-speaking countries, including Australia, Canada, New Zealand, the United States, Trinidad and Tobago, Jamaica, South Africa, the United Kingdom, and Ireland.
Sex offender registration does not exist outside of the Anglosphere, however.
The United States is the only country with a registry that is publicly accessible; all other countries in the Anglosphere have sex offender registries only accessible by law enforcement.
Three differing systems exist in determining offenders' inclusion in the registry: risk-based, sentence-length-based, and offense-based.
In risk-based systems, the offender is screened against a scientifically validated screening tool, and determination of inclusion is made according to the results.In sentence-length-based systems, offenders receiving sentences exceeding some determined length are included.In offense-based systems, registration is required when a person is convicted under one of the listed offenses requiring registration.Risk-based registries reflect the determined dangerousness of registered offenders, while sentence-length-based registries reflect the severity of the crime.Offense-based registries reflect neither the dangerousness of registrants, nor the severity of their crimes.UK, Canada, and Australia have adopted either risk-based- or sentence-length-based registry schemes. states applying risk-based systems are pressured by Federal Government to adopt offense-based systems in accordance with Adam Walsh Child Protection and Safety Act.