Click on a county or type in a city's name into the proper form on your computer, and blue squares appear across the interactive map — each blue speck representing a registered sex offender.
The Megan's law Web site displays these locations to help residents who want to keep track of registered sex offenders in their neighborhoods.
But some law enforcement officials who monitor sex offenders for a living say the Web site is not enough.
State Parole Agent Susan Kane supervises a unit of nine agents in Stockton who monitor sex offenders in San Joaquin County and some small neighboring counties, including Amador.
She said parents must keep a close eye on their children as well as use information tools such as the Megan's law Web site.
"That's the best way to protect our children," Kane said. "A lot of people still think it won't happen where they live, when in fact the threat could be right next door."
The Megan's law Web site was launched by the state Department of Justice in December 2004. Before then, the information was available only by visiting police stations and sheriff's offices or by calling a longdistance phone number.
Megan's law is named after 7-year-old Megan Kanka, a New Jersey girl who was raped and killed by a child molester who had moved across the street from her family without their knowledge. All states now have a form of Megan's law.
Approximately 63,000 Californians are required to register as sex offenders. On the Web site, home addresses are graphically displayed on maps in relation to someone's neighborhood, other addresses, parks and schools.
Just because a person is listed on the site does not mean the person is on probation or parole.
Convicted sex offenders are required to register for the rest of their lives, but the crime could have been committed years, even decades, earlier.
Kane said most people don't realize many of the registrants are not under regular supervision by law enforcement.
That is the public's biggest misconception about the Web site, said Jerry Powers, Stanislaus County chief probation officer.
"It creates a false sense of real-ity," he said. Powers encourages residents to be protective of their loved ones, but also asks them to report any suspicious behavior that might be occurring at the home of a registered sex offender.
"This guy might be handing out candy to children on Halloween, or it might be the house with the swimming pool where the nice man invites all the neighborhood kids over to swim," Powers said. "We all heard these horror stories before Megan's law."
California's version of Megan's law requires offenders to register yearly within five working days of their birthdays. It also requires that they register when they move.
Some sex offenders must update more often: Transients must update every 30 days, and sexually violent predators, every 90 days.
Offenders' photographs, names, aliases, ages, gender, race, offenses and physical descriptions are on the Web site.
Among those on the site is Roy Gerald Smith, a twice-convicted sex offender who pleaded guilty last week to killing Mary Morino-Starkey of Ripon and was sentenced to life in prison without possibility of parole.
His address on the Web site states: "INCARCERATED."
A state law passed last year has thrown a new wrinkle into the sex offender monitoring effort. Jessica's law was named for Jessica Lunsford, a 9-year-old Florida girl who was kidnapped, raped and suffocated by a convicted sex offender in 2005.
California voters passed the law with 70 percent approval. It requires parolee sex offenders to wear a global positioning system tracking device for life.
Powers said probation officers and parole agents closely monitor sex offenders with the help of other law enforcement agencies. They routinely share information with police and sheriff's officials about sex offenders in their jurisdictions.
"The more information on that Web site, the safer the community is," said Merced County Sheriff Mark Pazin.
On the Net: www.meganslaw.ca.gov.
Bee staff writer Rosalio Ahumada can be reached at firstname.lastname@example.org or 578-2394. The Associated Press contributed to this report.