A more thorough explanation:

A sex offender is a person who has been convicted of a sex offense. The Adam Walsh Child Protection and Safety Act of 2006 divides sex offenders into three tiers:

• Tier I: sex offenders who have been convicted of sex offenses not included in Tiers II and III.
• Tier II: sex offenders who have been convicted of an offense punishable by imprisonment for 1 year, and the offense is committed against a minor or involves using a minor in a sexual performance, soliciting a minor for prostitution, or producing or distributing child pornography.
• Tier III: sex offenders who have been convicted of an offense punishable by imprisonment for 1 year, and the offense is committed against a minor or involves the kidnapping of a minor.

The Department of Justice administers the national sex offenders’ registry. Sex offenders must appear in person to have a picture taken and verify registry information, such as their personal address. The frequency of appearance depends on the tier of the offender.

For example, a person who has been convicted of sexually abusing a minor would be considered a sex offender and would be required to register with the national sex offenders’ registry. Depending on the severity of the offense, the offender would be classified as a Tier I, II, or III sex offender and would be required to appear in person to verify their information at different intervals.