California was the first state in the nation to initiate a Sex Offender Tracking Program in 1947, but until 1996, when California Megan's Law (CML) was initiated, information about sex offenders was not publicly available.
Megan's Law is named after 7 year old New Jersey girl Megan Kanka, who was raped and killed by a known molester who lived across the street from her family. All states now have a form of Megan's Law.
On September 24, 2004, AB 488 was signed into law in California, providing the public Internet access to sex offender information at www.meganslaw.ca.gov. There are over 63,000 offenders in the CML database, including over 33,500 (now 40,500 as of Nov 2012) with home addresses listed due to the nature of their crimes and 12,000 (previously 30,000 - not sure why there's such a large decrease) listed by zip code only. Another 22,000 or so sex offenders are known by law enforcement but are not required to be listed on the website.
This is a website that deserves a look, particularly by anyone who is a parent. While the website is not meant to "punish" sex offenders, it is a useful awareness tool. The powerful search engine on the site allows you to search by name, address, city, zip and county, as well as within a 2 mile radius of parks and schools. You can also review the results of your search in both map and listing format, making it quite convenient.
Within seconds you can identify the 743 (as of November 2012) registered sex offenders in Ventura County, including photos, names, vital stats like date of birth, height and weight, their offenses and, where applicable, their addresses. The 5 cities with the largest sex offender counts are Oxnard (155), Ventura (143), Simi Valley (67), Camarillo (42) and Port Hueneme (40). Thousand Oaks and Newbury Park combined has 43 sex offenders.
The information in the CML database is not always up to date for each individual. The severity of the offenses for each individual vary from the more violent (rape, battery) to statutory rape, indecent exposure, etc. I see quite a bit of "LEWD OR LASCIVIOUS ACTS WITH A CHILD UNDER 14 YEARS OF AGE" in the database.
To protect yourself and your family from sexual assault, visit www.meganslaw.ca.gov/protect.aspx.