How do we stop predators?

Their first names have become synonymous with outrage and grief: Megan, Jessica, Samantha, Amber. Now, 17-year-old Chelsea King and 14-year-old Amber Dubois join the list of young lives likely cut short by sexual predators. And as in each of the previous cases, the heartbreaking discovery of the child’s body is followed by a renewed determination to enact stricter laws, to toughen sentences and intensify monitoring -- to do something, anything, to keep children safe.

And we do try. These murders continue despite sex offender registries and Jessica’s Law, which restricted where offenders can live and strapped global positioning systems on the ankles of about 6,700 perpetrators. They come after laws permitting chemical castration and the indefinite confinement of certain high-risk offenders to psychiatric facilities. And still, a registered sex offender, John Albert Gardner III, is suspected in both of the latest cases. What to do next?

Assemblyman Nathan Fletcher (R-San Diego), whose district includes Poway, home to King, and Escondido, home to Dubois, was right on target when he called last week for a complete evaluation of the state’s incoherent, patchwork approach to sex offenders. He was also right to hold off on the instantaneous creation of a “Chelsea’s Law.� For too long now, California has been throwing new sex offender laws against the wall and hoping they will stick. It’s time for lawmakers to assess which ones work and which ones do not.

Fletcher could begin by delving into the recent report by the California Sex Offender Management Board. It is startling reading for revelations about what data the state does not have. Although California has the largest population of registered sex offenders in the nation (in part because it began registering them in 1947), it has done little to analyze the behavior of this population. For example, according to the report, the state has never determined an accurate recidivism rate for sex offenders. Nor has it taken stock of how supervision, treatment, GPS tracking and sentencing affect a sex offender’s likelihood to re-offend. By now, for example, the state should know how many sex offenders enter treatment programs -- voluntarily or otherwise -- how many never do and the quality of those programs. But it doesn’t.

We must also explore the limits of sex offender registries and residency restrictions. Knowing where an offender lives is not the same as knowing where he or she is every moment of the day. GPS tracking was expected to address that gap, but in some ways Jessica’s Law has created new and unanticipated complications. The state now has a large population of sex offenders who, thanks to the law’s housing restrictions, are homeless. In 2007, shortly after the law was passed, only 88 sex offender parolees were homeless; in the years since, that number has grown to 2,088; the total number of “transient� sex offenders is more than 5,000. More and more are now dropping off the radar completely, failing to update their registry information -- a development that does not improve public safety.

California spent $65 million last year to track more than 6,000 sex offender parolees, but it is unclear which agency is responsible for monitoring them for life once their parole ends; nor is it clear whether the entire parolee population warrants tracking. California’s slender resources should target the offenders who pose the greatest threat. Is it reasonable that an 18-year-old boy who has consensual sex with a 13-year-old girl could land himself a lifetime spot on the sex offender registry with no chance of being removed? Fletcher has mentioned the importance of better prioritizing resources, and we hope he means it. What we have seen in the past after similar tragedies are measures hurried through the system to pacify a frightened, angry public, regardless of expense or efficacy.

It is also important to remember that the overwhelming majority of people who are sexually assaulted -- adults and children alike -- are preyed on by people with whom they are acquainted. Yet many of California’s policies seem to be aimed more at deterring assaults by strangers, the small fraction of offenses that garner the most attention and public outrage.

There will be a Chelsea’s Law when this inquiry phase is done, according to Fletcher. Well, maybe there should be and maybe there shouldn’t be. No one knows yet whether the measures we already have on the books are working as well as they should. If there is to be a new law, let’s be sure that it is bolstered by research and offers evidence that it will actually improve the public safety. The illusion of safety is not enough.