Tracking sex offenders.

Global Positioning System technology that helps motorists find their way is now being tapped to track some high-risk sex offenders. many lawmakers see electronic monitoring as a natural next step in laws that already require sex offenders to register their

Several states have statutory provisions regarding GPS tracking of sex offenders, including Florida, Louisiana, Massachusetts, Missouri, Ohio, Oklahoma, South Carolina and Tennessee. Minnesota and Texas are experimenting with the technology without state legislation.

People on the tracking system must wear the electronic waterproof ankle bands at all times and stay within a certain distance from their separate GPS transmitters, which can be carried on belts, in purses or set down on desks and tables when at work or home.

If the wearer ventures into "exclusion zones" around schools, parks and playgrounds, or out of "inclusion zones" such as workplaces or homes, the device sends an alert (which can be set up to be an e-mail, cell phone text message or fax) to the parole officer. Authorities can pinpoint the person's location at any moment, shown as a dot on a computer map that contains street names and the offender's traveling direction and speed. Parole officers keep logs of the offender's whereabouts.

Some experts who treat offenders say GPS tracking keeps offenders accountable for their behavior and helps them avoid risky situations, and it reassures the public. But opponents argue that the requirements are too onerous and not necessary or effective for all sex offenders.