California has lost track of more than 33,000 convicted sex offenders, according to recent research by the AP, although a law requires all rapists and child molesters to register each year to update their records in the Megan's Law database.

The Associated Press collected 2002 information over nine months. According to the data, the state does not know the whereabouts of 44 percent of the 76,350 sex offenders who registered with the state at least once.

"We don't know where they are," acknowledges Margaret Moore, who until recently ran California's sex offender registry.

And no one knows how many of these missing sex offenders have committed new crimes since being released. Nor does anyone know how many sex offenders never registered at all after leaving prison. The number of released sex offenders without current data registered with law enforcement could be much greater than 33,000.

Failing to register with law enforcement is in many cases a felony for convicted sex offenders. However, many overworked police departments are not following up.

Experts say police departments nationwide have a similar situation on their hands.

"It's not only in California," says Laura Ahearn, executive director of Parents for Megan's Law, a national victims' rights group. "We're expecting sex offenders to be reporting their addresses and that's a problem."

Megan's Law was named after 7-year-old Megan Kanka, girl who was raped and killed by a child molester who had moved in across the street from her. Megan's Law databases are supposed to help the public and police monitor convicted sex offenders by keeping track of their home and work addresses and other personal details. Adults can search the database at sheriffs' offices or police departments.

But no one audits California's database for accuracy or completeness.

Attorney General Bill Lockyer admits the databases are not being kept up. But he blames a lack of funding, not officers.

"Our system is inadequate, woefully inadequate," he says. "It can only be improved by putting money into the local law enforcement agencies. It's a matter of resources."